Features

Very efficient: Possibility of more than 95%

Wide vehicle recognition number range: 3.5 volts*to 16 volts

current mode running running , To achieve excellent lines and loads

Instant response

Always maintain high efficiency

output current

Light load low 160 Weian -staying machine current current current

Logic control micro power shutdown: IQ LT; 20μA

Short -circuit protection

extremely low dropout rate operation: 100%duty ratio

in a small number of board spaces Internal efficiency

At the time of the shutdown, the output can be kept higher on the outside

Provide 8 stitches SO packaging

Notebook computer and palm computer

Portable instrument

Portable instrument [ 123]

The digital device of the battery drive

Honeycomb phone

DC power distribution system

GPS system

Description

LTC #174; 1147 series is a controller with a lower -voltage switching voltage regulator with an automatic emergencies. These devices that drive external P channel power MOSFETs use the switch frequency of the constant constant of more than 400kHz to provide a ripple current in the current architecture of a constant current. The operating current can be performed through an external current. The wide input power range allows working between 3.5V*to 14V (maximum 16V). The constant closing time structure provides low leakage adjustments restricted by RDS (on) restricted by external MOSFETs and inductive resistance and current influenza resistance. LTC1147 The series has an automatic power -saving function emergencies operation, and operation below the level required for continuous operation. The standby power is in the vehicle identification number 10V (input 0). The load current operation in emergencies is usually 0-300 mAh. For applications that need to be more efficient, see the LTC1148 data table and application description 54.

Absolute AXI and Rate GS

Input power supply voltage (pin 1) 16V to -0.3V

Continuous output current (pin 8) 50 mAh

Index voltage (pin 4, 5)

Vehicle identification number ≥12.7 volts 13 volts to -0.3 volts

Vehicle identification number lt; 12.7 volts (vehicle identification number+0.3V ) To -0.3V

The working environment temperature range

LTC1147C 0 ° C to 70 ° C

LTC1147i – 40 ° C to 85 °C

Extended business

Temperature range (Note 4) –40 ° C to 85 ° C

Jienc (Note 1) 125 degrees Celsius

Storage storage storage Temperature range -65 ° C to 150 ° C

Lead temperature (welding, 10 seconds) 300 degrees Celsius

Electric characteristics TA 25 ° C, vin 10V, vshdn 0V, unless otherwise separate other There are instructions

Electric characteristics TA 25 ° C, vin 10V, vshdn 0V, unless there is another instructions

[

[ 123] Indicates that the regulatory temperature range is suitable for all regulations.

Note 1: TJ calculates PD according to the environmental temperature TA and power calculation

Based on the following formula:

LTC1147CN8-3.3/LTC1147CN8-5: tj TA+(PD PD ) (110 ° C/W)

LTC1147LIS/LTC1147IS8/LTC1147LCS/

LTC1147CS8-3.3/LTC1147CS8-5: TJ TA+(PD)

Note 2: Since the grid charge is transmitted at the switch frequency. See application information.

Note 3: In the application of placing RSENSE in the ground potential, the off -off time increases by about 40%.

Note 4: LTC1147C guarantees to meet 0 ° C to 70 ° C. Its design, characteristics, and expectations meet these requirements for extended temperature restrictions, but test LTC1147i is not performed at -40 ° C and 85 ° C. Extension temperature limit.

Note 5: LTC1147L/LTC1147L-3.3 allows operation to operate to vehicle identification number 3.5V.

Note 6: LTC1147L was tested under an external feedback resistor at the rated output voltage of 2.5V.

Typical performance features

Vehicle recognition number (needle pin 1): main electric needle pin. It must be closely separated from ground pins 7.

CT (pin 2): The frequency of CT from the external capacitor from the pin 2 to the grounding device. The actual frequency also depends on the input voltage.

ITH (pin 3): The decoupled point of the gain amplifier. The current comparator threshold increases with the increase of the pins 3 voltage.

Sensor - (pin 4): Connected to the internal resistor division to set the output voltage. Point 4 is also a current comparator.

Sense+(pin 5): The positive input of the current comparator. Sales 4 and 5The built -in offset between the between the current check threshold is set to the RSENSE settings.

SHDN/VFB (pin 6): During ground, the version of the fixed output LTC1147 series runs normally. Tingle 6 height keeps the P -channel MOSFET closure and LTC1147 is in a micro -power shutdown mode. CMOSTR, TF LT; 1 microsecond logic signal. Don't let the pin float. On the LTC1147L, the pin is used as an external resistor division from the output voltage.

Ground (pin 7): There must be two independent ground lines to: 1) COUT ( -) terminal, and 2) The cathode and CIN ( - )end.

P drive (pin 8): large current driver of P channel MOSFET. The voltage swing at this pin from the vehicle identification number to the ground.

Operation (reference function map)

The LTC1147 series uses a current mode and constant break time structure to switch the external P channel power supply MOSFET. The operating frequency is set by the external capacitor at the CT (pin 2). The output voltage is connected from the internal pressure sensor to Sense -(pin 4). The voltage comparator V, and the gain block G, the divided output voltage and reference voltage are 1.25V. In order to optimize the efficiency of the LTC1147 series, the two modes of automatic switching are continuous and continuous. When the device is in a working state, the voltage comparator is the main control component's emergency mode operation, and the output voltage in the continuous mode of the gain block control.

In the switch Open " cycle in the continuous mode