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AAT3190
Positive/Negative Charge Pump for Voltage Bias General Description
The AAT3190 charge pump controller provides the regulated positive and negative voltage biases required by active matrix thin-film transistor (TFT) liquid-crystal displays (LCDs), charge-coupled device (CCD) sensors, and organic light emitting diodes (OLEDs). Two low-power charge pumps convert input supply voltages ranging from 2.7V to 5.5V into two independent output voltages. The dual low-power charge pumps independently regulate a positive (VPOS) and negative (VNEG) output voltage. These outputs use external diode and capacitor multiplier stages (as many stages as required) to regulate output voltages up to ±25V. Built-in soft-start circuitry prevents excessive inrush current during start-up. A high switching frequency enables the use of small external capacitors. The device’s shutdown feature disconnects the load from VIN and reduces quiescent current to less than 1.0µA. The AAT3190 is available in an MSOP-8 or TSOPJW-12 package and is specified over the -40°C to +85°C operating temperature range.
Features
• • • • • • • • • • • • •
ChargePump™
VIN Range: 2.7V to 5.5V Adjustable ± Dual Charge Pump Positive Supply Output Up to +25V Negative Supply Output Down to -25V Up to 30mA Output Current 1.0MHz Switching Frequency <1.0µA Shutdown Current Internal Power MOSFETs Internally Controlled Soft Start Fast Transient Response Ultra-Thin Solution (No Inductors) -40°C to +85°C Temperature Range Available in 8-Pin MSOP or 12-Pin TSOPJW Package
Applications
• • • • • CCD Sensor Voltage Bias OLEDs Passive-Matrix Displays Personal Digital Assistants (PDAs) TFT Active-Matrix LCDs
Typical Application
INPUT
IN
EN
EN
DRVN
AAT3190
DRVP FBN
NEGATIVE OUTPUT
REF FBP GND
POSTIVE OUTPUT
3190.2005.03.1.0
1
AAT3190
Positive/Negative Charge Pump for Voltage Bias Pin Description
Pin #
MSOP-8 TSOPJW-12
Symbol
FBP
Function
Positive charge pump feedback input. Regulates to 1.2V nominal. Connect feedback resistive divider to analog ground (GND). Enable input. When EN is pulled low, the device shuts off and draws only 1.0µA. When high, it is in normal operation. Drive EN through an external resistor. Internal reference bypass terminal. Connect a 0.1µF capacitor from this terminal to analog ground (GND). External load capability to 50µA. REF is disabled in shutdown. Negative charge pump regulator feedback input. Regulates to 0V nominal. Connect feedback resistive divider to the reference (REF). Positive charge pump driver output. Output high level is VIN and low level is PGND. Ground. Negative charge pump driver output. Output high level is VIN and low level is PGND. Input voltage: 2.7V to 5.5V.
1
5
2
4
EN
3
3
REF
4
2
FBN
5 6 7 8
12 8, 9, 10, 11 7 1
DVRP GND DRVN VIN
Pin Configuration
MSOP-8 (Top View) TSOPJW-12 (Top View)
FBP EN REF FBN
1
8
VIN DRVN GND DRVP
2
7
3
6
4
5
VIN FBN REF EN FBP N/C
1 2 3 4 5 6
12 11 10 9 8 7
DRVP GND GND GND GND DRVN
1 2
2
.