Generally explained

LP2967 is a 150 mAh, and the dual fixed output voltage regulator aims to provide ultra -low voltage drop and low noise for the application of battery power. Using optimized VIP (vertical integrated PNP) process, LP2967 provides unparalleled performance in all the vital specifications of battery design:

Falling voltage: Usually 240 mm under 150 mAh load is 240 m Fu, and each output is 6MV under the 1mA load.

Ground pin current: 150 mAh load is usually 1 mAh, and each output is 200 μA under the 1MA load.

Enhancement stability: LP2967 stability, output capacitor ESR as low as 5 m , allows capacitor with ceramic output terminals.

Sleep mode: The static current is less than 2 μA when the SD is pulled down.

Minimum size: Micro SMD packaging is absolutely minimum.

Accuracy output: 1.25%.

Low noise: By adding a 100NF bypass capacitor, the output noise can be reduced to 30 μV (typical value). Provide multiple voltage options from 1.8V to 5.0V. For customized voltage, please consult the factory.

Features

Ultra -low drop voltage

Guarantee 150 mAh output current, 300 mAh peak

minimum size (miniature SMD packaging)

The least external component is required

Use 2.2 μF 钽 or ceramic capacitor stability

Output voltage accuracy ± 1%

lt; static current when 2 μA shuts down [123 ]

Wide power supply voltage range (maximum 16V)

Low voltage area: 0.3 (10 hz to 1 mHz)

overcurrent protection

[

[ 123] 40 ; C to+125 ; C knot temperature range

Provides customized voltage

Mobile

Palm computer/laptop computer

Personal digital assistant (PDA)

Camera, personal stereo sound and camera

*SD1 and SD2 must be necessary Take the initiative to terminate. If they do not need their functions, link them with VIN.

** Show the minimum capacitor to ensure stability (which can increase without restrictions).

*** Reduce the output noise (ifApplication is not the key to noise, it can be omitted). Use the leakage current with a very low ceramic or film type.

Absolute maximum rated value (Note 1)

If you need military/aerospace special equipment,

Storage temperature range 65 ; C to+150 #730; c

Diversion temperature. (Infrared back welding, 10 seconds) 245 ; C

The cushion temperature. (Infrared back welding, 10 seconds) 245 ; C

The working knot temperature. Scope 40 ; C to+125 ; C

Power consumption (Note 4) Internal limited

ESD rated value (Note 2) 1.5kV

[ 123] Input power supply voltage (survival) 0.3V to+16V

Input power supply voltage (work) 2.1V to+16V

The input voltage (survival) 0.3V to+16V

output voltage (survival) (Note 4)

Short -circuit protection

Input output voltage (survival), (Note 5) [5) 123]

Electrical characteristics

The limit of the standard font is suitable for TJ u003d 25 ° C, and the limit of black bodies is suitable for the entire work temperature range. Unless there are other regulations, VIN u003d VO (nominal value)+1V, IL u003d 1MA, CIN u003d 1 μF, COUT u003d 4.7μF, von/off u003d 1.6V.

Note 1: Absolute maximum rated value indicates the limit of damage to the device. When operating the device, the electrical specifications do not apply more than the rated working conditions.

Note 2: The rated value is suitable for the human mode. The 100PF capacitor discharges to each pin through 1.5K the resistor is discharged.

Note 3: The maximum allowable power loss is calculated in PDMAX u003d (tjmax-ta/θja). Among them, TJMAX is the highest knot temperature, TA is the ambient temperature, and θJa is the knot of the environmental thermal resistance specified by the packaging. Therefore, the maximum power consumption must be reduced at high temperature and is limited by TJMAX, θJa and A.

Note 4: If you use it in the dual power system where the regulator load returns the negative power supply, the LP2967 output must be ground pipe pliers.

Note 5: The output PNP structure contains a diode between VIN and VOUT terminals, usually reverse bias. The reversal polarity from VIN and VOUT will open this diode.

Note 6:The load adjustment offset exceeding the temperature is included in the output voltage tolerance. When the output voltage difference is within the range of 100mv, the voltage difference is defined as the minimum value of the output voltage 1V difference.

Typical performance characteristics, unless there are other regulations: CIN u003d 1 μF, COUT u003d 4.7 μF, von/off u003d 1.6V, IL u003d 1MA, TA u003d 25 ; C.

Program prompt

outer capacitor

lp29677 The low -voltage differential regulator requires two external capacitors, CIN and COUT to ensure the output stability of the device. CBYPASS can be used to reduce output noise. This must be correctly selected by the capacitor value and ESR value according to the capacitors and ESR values u200bu200bof all three capacitors.

Input a capacitor

The input capacitor with the minimum electricity value of 1 μF requires an infinite increase in electricity capacity between LP2967 input and grounding). The placing distance of this capacitor shall not exceed 0.5 distance input pin inch, and return to a clean analog ground. You can use any quality ceramics or cricket for this capacitor.

Output capacitor

The output capacitor must meet the requirements of the minimum capacitor value of 2.2 μF and have an appropriate ESR (equivalent series resistance) value. LP2967 is actually designed for output capacitors used for ceramics or pupa. It uses the allowable regulator output capacitor ESR to be as low as 4, stabilizing M It can also be so attractive and cost -effective due to size because of size.

Important matters: The output capacitor must maintain the application of the stable area of u200bu200bthe stable area within the entire working temperature range of ESR to ensure stability. The minimum requirement for output power is 2.2 μF. The size of the output capacitor can be increased infinitely. It is important to remember the tolerance of the capacitor and the changes in temperature. When selecting the output, the minimum output required for the capacitor must provide the capacitor range at the entire operating temperature.

Air load operation

If the 2.2μF output capacitor is used, the minimum stable ESR is used as a load current When it was lower than 1 ma, the value rose to about 0.5 . If the minimum output load lt; 1MA (COUT u003d 2.2 μF), A should use 钽 output capacitors (A ceramic will be too low). It should be noted that if 4.7 μF (or larger) uses the output capacitor, the components are completely stable to the 钽 or ceramic current from vacant to full -load output.

Wingrsening container

The 10 NF capacitors are prominently connected to the barrier to the feet to reduce the adjustmentThe noise output of the joint. It should be pointed out that the capacitor is directly connected to the benchmark circuit of high impedance band gap. Because this circuit has only a few Weian current flowing into the node, any significant load on the node will cause the variable voltage of the adjustment output. Therefore, the DC leakage current can not exceed 100 mAh through the noise bypass, and the optimal output voltage accuracy should be maintained as low as possible. The most suitable capacitor type bypass power container is ceramic and film capacitors. High -quality NPO or COG medium ceramic capacitor usually leaks very low. 10 NF polypropylene and polycarbonate film capacitors are installed and packaged in small surfaces, usually with extremely low leakage currents.

Capacitor features

Ceramics

The minimum ESR value of ceramic capacitors allows them to eliminate high -frequency noise. The output of this LP2967 requires at least 2.2 μF capacitors. The typical 2.2μF ceramic capacitor ESR is in the range from 4 m to 20 m , which is easy to meet the stability of ESR limit LP2967 requirements. The capacitor of a disadvantage of ceramic capacitors can be temperature. Most large -capacity ceramic capacitors are made of Z5U or Y5V temperature characteristics, resulting in a decrease of more than 50%of the capacitance. When the temperature increases from 25 degrees Celsius to 85 degrees Celsius, it may be output because it will drop to about 1 μF at high environmental temperature at high environmental temperature. Essence This may cause the LP2967 operating system to collapse. If the output terminal uses the Z5U or Y5V capacitor, the minimum capacitor value must be 4.7 μF. A better choice for the temperature coefficient of ceramic capacitor is X7R or X5R, which controls the capacitor to ± 15%throughout the temperature range. Unfortunately, in the X7R medium, not all manufacturers can provide greater capacitance.

12

For LP2967, the capacitor is not as used as a ceramics for output capacitors, because when comparing equivalent capacitors and voltage rated values u200bu200bin the range of 2.2 μF to 4.7μF, they are usually more expensive more expensive capacitance.良 The capacitor has good temperature stability: Test 4.7μF, showing that the capacitor of 10%decrease when the temperature decreases when the temperature is reduced from+125 ° C to the 40 ; C, and ESR is in the same temperature range. Increased blood sink When the quality is in a critical state, the temperature will cause oscillation to use capacitors, and the upper limit of the ESR value is more than.

Aluminum

Large -dimensional aluminum electrolytic capacitors make it unattractive when using it with LP2967. Their ESR characteristics are not suitable for LDO regulator. The ESR of the aluminum electrolyte is higher than that of 钽, and its changes are very temperature. A typical aluminum electrolytic can show that when it becomes 20 ; C to 40 ; Because the electrolyte will freezeEssence

Two LDO regulators in LP2967 have an independent closing pin. Turn off the low -logical level signal of SD1 or SD2, which will turn off the corresponding regulator output VOUT1 or VOUT2. Insert SD1 and SD2 must be tied to VIN for correct operations in the following circumstances to terminate the function without stopping.

Reverse current path

LP2967 internal power transistor has an inherent parasitic diode. When working normally, the input voltage is higher than the output voltage, and the parasitic diode reverse bias. However, if the output is pulled to the application input, and then the current flows from the output flow to if the parasitic diode is pressed forward input. This output can be pulled to the input terminal as long as the current parasitic diode is limited to 150mA.

Application prompt (continued)

Maximum power dissipation capacity each output pin LP2967 can provide Gundam 150 mAh in the entire work knot temperature range. However, the maximum output current must be at a higher environmental temperature to ensure that the joint temperature does not exceed 125 ° C. Under all possible conditions, the joint temperature must be under operational conditions within the specified range. LP2967 packaged in MSOP-8 and 8-bump micro-patch. The ambient temperature coefficient (θJa) connected to the MSOP-8 packaging is 235 ° C/W, and the minimum copper area of u200bu200bthe 8 convex patch is 220 ; C/W

The device consists of: pd u003d (vin # 8722; vout1) IOUT1+(VIN Vout2) The maximum power consumption of iOUT2 device

can be calculated through the following formulas: pdmax u003d (TJMAX TA), TJMAX is specified The highest knot temperature (125 ° C), TA is the highest ambient temperature.