Features

Integrated synchronization rectifier

Power conversion efficiency ( gt; 95%)

In the case of the power supply voltage to 0.9 V, the working voltage as low as 0.8 V Start to full load

200mAh output current from 0.9 V power supply

The power -saving mode improving efficiency under low output current

Automatic discharge allows to allow during the shutdown period during the downtime period. Discharge output capacitors

Equipment static current is less than 50 μA

During the turnover of the inverter, it is easy to use

integrated anti -interference switch by being isolated from the battery

] Integrated low battery comparator

Micro 10 pins MSOP or 3 mm x 3 mm qfn packaging

Provides EVM (

TPS6101X

EVM-157)

Application

All single batteries or dual battery power supply products

- Internet audio player

- Passing machine

- Portable medical diagnosis equipment

- Remote control

- Wireless headset

TPS6101X device is a booster converter, which is usually used by single single. A system of battery or dual battery nickel -cadmium (NICD), nickel -metal hydride (NIMH) or alkaline battery operation.

The output voltage of the converter can be adjusted from 1.5 volts to a maximum 3.3 volts through an external resistor, or fixed inside the chip. These devices provide an output current of 200 mA, with a power supply voltage of only 0.9 volts. The converter starts with a full load when the power supply voltage is only 0.9 volts, and it is maintained when the power supply voltage drops to 0.8 volts.

The transformer is based on a fixed frequency, current mode, and pulse width modulation (PWM) controller, which automatically enters the power -saving mode during light load. The built -in synchronous rectifier is adopted, and the two polar pipes are not required to improve the system efficiency. The current through the switch is limited to a maximum value of 1300 mAh. Converters can be disabled to minimize battery consumption. During the shutdown, the load is completely isolated from the battery.

The automatic discharge function allows discharge output capacitors in the shutdown mode. This is particularly useful when the microcontroller or memory is powered, because the remaining voltage on the output capacitor may cause the application to fail. When programming Aden pins, the automatic discharge function can be disabled. When the converter enters the non -continuous pitch mode, the low EMI mode is used to reduce interference and radiation electromagnetic energy. The device is encapsulated in micro -small space to save 10 stitches MSOP packaging. TPS61010 also offers 3 mm x 3 mm 10Pack QFN packaging.

Parameter measurement information

Circuit used for typical characteristics

Detailed description

Overview

[

123] This converter is based on fixed frequency, current mode, and pulse width modulation (PWM) boost converter and the concentration rectifier built. This device limits the current of the power switch based on the pulse. TPS6101X enters the power -saving mode during light load. In this mode, TPS6101X is switched only when the output voltage jumps below the set threshold voltage. It uses one or more pulse to increase the output voltage. Once the output voltage exceeds the set threshold voltage, it will enter the power -saving mode again. When the device is closed, the load is completely isolated from the battery. The automatic discharge function allows discharge output capacitors during shutdown. If the pin is connected to the VBAT, the automatic discharge function will be enabled; if the Aden is connected to the GND, the automatic discharge function is disabled.

Function box diagram

Fixed output voltage version TPS61011 to TPS61016

Function box diagram (continued)

The adjustable output voltage version TPS61010

9.3 Feature description

9.3.1 controller circuit

This device Based on the current mode control the topology structure, the output voltage is adjusted using a constant frequency pulse width modulator. The controller limits the current of the power switch based on the pulse. This device integrates the current sensing circuit without additional components. Due to the nature of the BOOST converter's topology, the peak switch current is the same as the peak inductor current. Under normal working conditions, this will be limited by the integrated current limit circuit.

The control loop must be external compensation through the R-C-C network connected to the COMP pin.

9.3.2 Synchronous rectifier

This device integrates N channels and P vocations MOSFET transistors, realizing synchronous rectification. No additional Schottky diode is needed. Due to the use of integrated low RDS (on) PMOS switches for rectification, power conversion efficiency reached 95%.

During the stoppage of the inverter, a special circuit was used to open the load from the input end. In the traditional synchronous rectifier circuit, the rear diode of the high side PMOS is positively biased when the turning is off, allowing the current to output from the battery flow to the output. However, the device uses a special circuit to disconnect the back door diode of the high side PMOS. Therefore, when the regulator is not enabled (EN low), the power supply is disconnected from the power supplyroad.

The benefit of this function for system design engineers is that the battery will not be exhausted during the closure of the converter. Therefore, system designers do not need to work to ensure that the output of the battery and the converter is disconnected. Therefore, it will improve design performance without increasing additional costs and board space.

Feature description (continued)

Power -saving mode

TPS61010 design is designed to work efficiently within the wide output current range. Even in the case of light negative load, because the switching frequency is effectively reduced and the switch loss of the converter is minimized, the efficiency is still high. If you meet certain conditions, the controller will enter the power -saving mode. In this mode, the controller only turns on the transistor only when the output voltage is lower than the set threshold voltage. It uses one or more pulse to increase the output voltage. Once the output voltage exceeds the set threshold voltage, it will enter the power -saving mode again.

Device enable

When EN is set to GND, the device is closed. In this mode, the regulator stops switching, and all internal control circuits, including the low battery comparator, are turned off, and the load and input disconnect (as described in the synchronous stream part above). This also means that the output voltage may be lower than the input voltage during the downtime.

When EN is set to be high, the device is put in operation. During the startup process of the converter, the duty cycle is limited to avoid the peak current current from the battery. The limit is set by the current limit circuit, and it is proportional to the voltage on the COMP pin.

IOU locking (UVLO)

If the power supply voltage on the VBAT is lower than about 0.7 V, the UVLO function can prevent the device from starting. The implementation of this UVLO function is to prevent the converter from failing. During operation, when the battery is discharged, if the voltage on the VBAT drops to about 0.7 V, the device will automatically enter the shutdown mode.

Automatic discharge

The automatic discharge function is very useful for the application of μC, μP or memory to ensure the application of the system during shutdown.

The automatic discharge function is set at high when the ADEN is set to high, and it is disabled when ADEN is set to GND. When the automatic discharge function is enabled, the EN is set to GND, and the output capacitor will be discharged after the device is turned off. The capacitors connected to the output end are discharged by 300Ω integrated switch, so the discharge time depends on the total output capacitor. After discharge, the remaining voltage on VOUT is less than 0.4V.

Low battery detection circuit (LBI and LBO)

Low battery detection circuit is usually used to monitor battery voltage, and an error flag is generated when the battery voltage is reduced to the user settings below the threshold voltage. This function is activated only when the device is enabled. When the device is disabled, the LBO pin is high impedance.When the voltage on the LBI pin is reduced to the set threshold voltage of 500 mv ± 15 mv (equal to internal reference voltage), the LBO pin becomes a low activation state. The battery voltage during the detection circuit can be programmed by the resistance division connected to the LBI pin. The resistor division pressure reduces the battery voltage to a voltage level of 500 MV, and then compares it with the LBI threshold voltage. The LBI pin has a built -in lag of 10 MV. For more detailed information about LBI threshold programming, see the application part.

If the low -power detection circuit is not used, the LBI pin should be connected to the GND (or VBAT), and the LBO pin can be kept unconnected. Don't let LBI float.

Anti -infringement switch

This device integrates a circuit. When the converter enters the non -continuous current mode, the bell that usually appears on the SW node is eliminated. In this case, the current of the inductance becomes zero, and the PMOS switch is closed to prevent the reverse current of the battery from returning the battery from the output capacitor. Because the remaining energy is stored in the parasitic elements of semiconductor and inductors, the bell is generated on the switching foot. The integrated anti -vibration switch is sandwiched inside the VBAT to suppress this sound.

Feature description (continued)

The adjustable output voltage

Finally tun the device fixed in the output voltage, so that the output voltage accuracy reaches ± 3%.

The accuracy of the adjustable version depends on the accuracy of the internal voltage benchmark, the controller topology and the accuracy of the external resistance. The accuracy of the reference voltage, load, and temperature is ± 4%. The controller switches between the load current in the fixed frequency and the pulse skip mode. This will add a offset to the output voltage equivalent to VO 1%. The tolerance of the resistance in the feedback pressure device determines the accuracy of the entire system.

Application and implementation

Note

The information in the application part of the following application is not part of the TI component specification, TI does not guarantee its accuracy or integrity. TI's customers are responsible for determining whether the part is suitable for its purpose. Customers should verify and test their design implementation to confirm the system function.

Application information

The device is designed within the range of input voltage supply range between 0.9V and 3.3V, and the maximum switching current is limited to as much as 1300mA. This device works under the middle to heavy load conditions, and works in power -saving mode under light load conditions. In the pulse width modulation mode, the TPS6101X converter works with a nominal switch frequency of 500kHz. With the reduction of the load current, the converter enters the power -saving mode, reduces the switching frequency, reduces the IC static current, and achieves high efficiency within the entire load current range.

Typical application

1 1.8-mm maximum power supply, using low cuttingFacial component, single battery input

Detailed design program

TPS6101X boost converter series is suitable for the typical terminal voltage between 0.9 v and 1.6 V Single battery nickel -cadmium or nickel -metalized battery power supply system. It can also be used for a system for dual -battery nickel -cadmium or nickel -metal hydride batteries between the typical stacking voltage between 1.8 V and 3.2 V. In addition, single batteries or dual batteries can be used as power supply in systems using TPS6101X, primary and secondary alkaline batteries.

Programming the TPS61010 adjustable output voltage device

The output voltage of TPS61010 can be adjusted by an external resistor division. The typical value of the voltage on the FB pin is 500 MV at the fixed frequency and 485 MV in the power -saving operation mode. The maximum allowable value of the output voltage is 3.3 V. The current of the resistor division should be about 100 times larger than the current entering the FB pin. The typical current of the FB pin is 0.01 Wei'an, and the voltage on the R4 is usually 500 millivolves. Based on these two values, the recommended value of the R4 is within the range of 500 kΩ, so that the sterilizer current can be set to 1 μA. Therefore, according to the required output voltage (VO), the value of the resistor R3 can be calculated using the formula 1. #230; V #230; V #230; O type O type

For example, if the output voltage of 2.5 V is required, R3 should select 2 MΩ resistor

123]

The typical application circuit selected by the adjustable output voltage

The output voltage of the output voltage changes with the change of the output current. Due to the internal grounding of the equipment caused by the high switching current, the internal reference voltage and voltage on the FB pin increased with the increase of the output current. Because the output voltage follows the voltage on the FB foot, the output voltage increases at a rate of 1 MV at an increase of 1 MV per 1-MA. In addition, when the converter enters the pulse skip mode under the output current of 5 mAh and below, the output voltage decreases due to the lag of the controller. This lag is about 15 millivoli and measures on the FB pin.

Low battery comparator threshold voltage programming

The current through the resistor division should be about 100 times larger than the current entering the LBI pin. The typical current entering the LBI pin is 0.01 Weire. The voltage of the pass through R2 is equal to the reference voltage generated on the chip, and its value is 500 mv ± 15 mv. Therefore, the recommended value of R2 is within the range of 500 kΩ. As a result, the value of the resistance R1 depends on the minimum battery voltage VBAT required, which can be calculated using formula 2.

For example, if the low battery detection circuit should be introduced at LBO when the battery voltage is 1VThe error condition on the foot should be the resistor within 500 kΩ range of R1. The output of the low battery comparator is a simple leakage output. When the battery voltage is lower than the programming threshold voltage on the LBI, the output will become a low activation state. The output requires a pull -up resistor with a recommended value of 1 MΩ, and can only be pulled to VO. If it is not used, the LBO pin can be kept floating or binded to GND.

Sensor selection

The booster converter usually requires two major passive components to store energy. One boost inductor and a storage capacitor are needed at the output end. To choose the voltage voltage, it is recommended to make the possible inductance peak current lower than the current limit threshold of the power switch. For example, at the output voltage of 3.3V, the current limit threshold of the TPS61010 switch is 1100mA. The maximum peak current of the induction and switch depends on the output load, input (VBAT) and output voltage (VO). The estimation of the maximum average inductor current can be completed with formula 3.

For example, for the 100MA output current at 3.3V, at least 515mA current at a minimum input voltage of 0.8V is overcurrent.

Selecting the second parameter of the electrical sensor is the current ripple required in the inductor. Under normal circumstances, it is recommended that work ripples are less than 20%of the average inductor current. Smaller ripples reduce the magnetic stasis loss of the inductance, as well as output voltage ripples and electromagnetic interference. However, the adjustment time when the load changes will increase. In addition, the larger inductance will increase the total system cost.

Use these parameters to calculate the value of the inductance by using these parameters.

Parameter 7 is the switching frequency, and ΔIL is an inductive ripple current, that is, 20%× IL.

In this example, the required inductor has a value of 12 μH. Using the calculation value and the calculated current, you can choose the appropriate inductor. It must be noted that the load transient and loss in the circuit may cause higher current estimated in Equations 3. In addition, the inductance loss caused by magnetic stasis losses and copper loss is also the main parameter affecting the total efficiency of the circuit.

Capacitor selection

Define the main parameters required for the output capacitor is the maximum allowable output voltage ripple of the converter. This ripple is determined by two parameters of the capacitor, capacitance and ESR. Assuming that ESR is zero, the minimum capacitor required to define the ripples is calculated using equation 5.

Parameter F is the switching frequency, and ΔV is the maximum allowable ripple.

When selecting a ripple voltage of 15 MV, the minimum capacitor of 10 μF is required. Due to the ESR of the output capacitor, the total ripples are large. This additional component of the ripple can be calculated with square 6.

Use low ESR as aThe 300 MΩ pillar container can produce an extra ripple of 30 MV. The total ripple is the sum of ripples caused by capacitors and capacitance ESR. In this example, the total ripple is 45 MV. It is possible to improve the design by expanding the capacitor or using smaller capacitors to reduce ESR, or use better capacitor (such as ceramics) with lower ESR to improve design. For example, use ESR 10 μF ceramic capacitors with ESR on the evaluation module (EVM). Weighing the performance and cost of the converter circuit.

It is recommended to use 10 μF input capacitors to improve the transient characteristics of the regulator. It is recommended to use ceramic container or 钽 capacitor, and placed 100 NF ceramic capacitors in parallel near IC.

Control loop compensation

In order to stabilize the control loop of the transformer, the R/C/C network must be connected to the comp pin. The pole and output capacitors of the inductor L1 must be compensated by the zero point caused by the ESR and the capacitor. The network shown in the figure meets these requirements.

Control loop compensation

Resistance RC and capacitance CC2 depend on the inductance. For the 10 μH electrochemical device, the capacitance of CC2 should be selected as 10NF, or in other words, if the inductor is XXμH, the selected compensation capacitor should be XX NF, the same value. Then, according to the time constant of the R/C network RC and CC2, the value of the compensation resistance is selected. Therefore, for 33 NF capacitors, the 33 kΩ resistor should be selected for RC.

The capacitor CC1 depends on the ESR and capacitance value of the output capacitor, and the value for the selection for RC. Its value is calculated with square 7.

250 mAh power input with two batteries

TPS6101X 2 core AA battery input and application diagram greater than 250 mAh output current.

250 mAh power supply, with two batteries input

dual output voltage power supply for DSP

TPS6101X application schematic, With 3.3Vout I/O power supply and 1.5VOUT rear LDO DSP core power supply

U2 TPS76915 C1 10 F X5R ceramic, TDK C3216x5R0J106 C4 22 F X5R ceramic, TDK C3225X5R0J226 L1 10 H Sumida CDRH6D38 μM

The dual output voltage power supply for DSPS

The power supply with auxiliary positive output voltage

TPS663.3Vout and 6VOUT apps of the 101X with charge pump.

DS1 BAT54S C1 10 F X5R ceramic, TDK C3216x5R0J106 C4 22 F X5R ceramic, TDK C3225X5R0J226, C6 1 F X5R ceramic, C7 0.1 F X5R ceramic, L1 10 H Sumida CDRH6D38–100

The power supply with auxiliary positive output voltage

Auxiliary output voltage power supply

TPS6101X charging pump 3.3Vout and -2.7Vout's application diagram.

TPS6101X EVM circuit diagram

Power suggestion

This device is designed in the input voltage range of 0.9 V to 3.3 V. The input voltage must be well adjusted. If the input power distance converter is more than a few inches, in addition to the ceramic road capacitor, additional large -capacity capacitors may be needed. The typical option is an electrolytic capacitor or a cricket capacitor with a usage value of 47μF.

Layout Guide

For all the switching power supply, the design is an important step in the design, especially at the peak current and high switching frequency. If the layout is not carefully, the regulator may have stability problems and electromagnetic interference problems.

Therefore, as shown in Figure 32, a wide and short record of the main current path use. Input capacitors, output capacitors, and inductors should be as close to the integrated circuit as possible. As shown in Figure 32, the impact of ground noise was minimized with public ground nodes. The compensation circuit and the feedback frequency division should be as close to the integrated circuit as much as possible. In order to arrange control grounding, it is recommended to use a short trajectory, which is separated from the power grounding trajectory. As shown in the layout diagram in Figure 32, the two ground end is connected to the ground pins of IC. This can avoid the problem of ground offset caused by the overlap due to the overlap of the power supply and the control of the ground current.

layout example

Figure

Layout example (continued)

]

TPS6101X EVM component placement (actual size: 55.9 mm x 40.6 mm)

Layout examples (continued)

TPS6101X EVM underlying layout (actual size: 55.9 mm x 40.6 mm)

Thermal factors

In the low section and fine -spacing surface installation packageCircuit usually needs to pay special attention to power consumption. Many issues related to the system, such as thermal coupling, airflow, increased heat sinks, and convection surfaces, and the existence of other heating components, will affect the power consumption limit of the given component.

The three basic methods of improving thermal performance are:

Improve the power consumption capacity of PWB design

Improving the thermal coupling of the component and PWB

in the system in the system The highest temperature (TJ) of the TPS6101X device was introduced in the introduction of airflow

The TPS6101X device is 125 ° C. The thermal resistance of the 10 -needle MSOP package (DGS) is Rθ 161.8 ° C/W. The specified regulator work ensures that the highest ambient temperature (TA) is 85 ° C. Therefore, the maximum power consumption is about 247 mW. If the maximum environmental temperature of the application is low, it can dissipate more power. Youth Achievement Organization

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Equipment bracket

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