austria
micro
systems
AS3681
Power & Lighting
Management Unit
1 General Description
The AS3681 is a highly-integrated,
ultra-flexible
CMOS
Power- and Lighting Management
Unit to supply power to
LCD- and camera-modules in
mobile telephones,
and other 1-cell Li+ or 3-cell NIMH powered
devices.
The AS3681 incorporates one low-power, low-dropout reg-
ulator (LDO), one Step Up DC/DC Converter for white
backlight LEDs, one high-power Charge Pump for camera
flash LEDs, one Analog-to-Digital Converter, support for up
to 11 current sinks, a serial interface, and control logic all
onto a single die.
The linear analog regulator features extremely high analog
performance regarding:
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Product Brief
Supports up to 11 Current Sinks
- Three Programmable (4-bit) from: 10 to 150mA
resp. 300mA
- Two Programmable (4-bit) from: 2.5 to 37.5 mA
- Three Programmable (4-bit) from: 2.5 to 37.5 mA for
RGB LEDs
- Three Programmable (4-bit) from: 2.5 to 37.5mA for
General Purpose Applications
- Programmable Hardware Control (Strobe, PWM)
- Selectively Enable/Disable Current Sinks
10-bit Successive Approximation ADC
- 11µs Conversion Time
- Two Selectable Inputs: GPIO0 and GPIO1
Four General Purpose Inputs/Outputs
- Digital Input, Digital Output, and Tristate
- Programmable Pull-Up, and Pull-Down
- GPIO2 can be used as Camera Flash Strobe
Negative or High-Voltage Charge Pump
- Regulated Output Voltage, Programmable by Dual
Resistors e.g. -6V, 10mA for OLED or ±15V, 5mA for
TFT
- ± 5% Accuracy
- Requires Few External Components
Standby LDO
- Regulated 2.5V
- Maximum Output Current 10mA
- Always On (Supplies Internal Digital Blocks)
- 3µA Quiescent Current
Wide Battery Supply Range: 3.0 to 5.5V
Serial Interface Control
On-Chip Bandgap Tuning for High Accuracy (±1%)
Overcurrent and Thermal Protection
32-Pin, Small Form-Factor QFN Package
(5 x 5 x 1mm, 0.5mm pitch), Enhanced Thermal Charac-
teristics
1 Watt Power Dissipation @ TAmbient = 70ºC
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Noise (< 30µVrms from 100Hz to 100kHz)
Line/load Regulation
(<1mV Static and <20mV Transient)
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Power Supply Rejection (>70dB@1kHz)
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Ultra-Low Power Consumption
(1µA Shutdown, 6µA Standby)
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LDO output voltages and output currents are programma-
ble via a serial interface.
2 Key Features
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Programmable High-Performance Regulator
- Low-Noise LDO (1.8 to 3.4V, 100mA)
- 2.8V Default Output Voltage after Power-up
- 3µA Quiescent Current in Standby (I
out
<5mA)
- Turns On/Off with Rising/Falling Edge of GPIO
Supply Voltage
- Programmable via Serial Interface
High-Efficiency Step Up DC/DC Converter
- Up to 25V/50mA for White LEDs
- Programmable Output Voltage with External Resis-
tors and Serial Interface
High-Efficiency High-Power Charge Pump
- 1:1, 1.5:1 and 2:1 Mode
- Output Current up to 400mA
- Efficiency up to 95%
- Only 4 External Capacitors Required:
2 x 1µF Flying Capacitors, 2 x 2.2µF Input/Output
Capacitors
- Supports LCD White Backlight LEDs,
Camera Flash White LEDs, and Keypad Backlight
LEDs
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3 Application
Power- and lighting-management for mobile telephones
an
d other 1-cell Li+ or 3-cell NiMH powered devices.
© 1997-2004, austriamicrosystems
USA, Inc. 8601 Six Forks Road, Suite 400 Raleigh,NC 27615 USA.
All Rights Reserved.
www.austriamicrosystems.com
Revision 1.0
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AMSCO [ AUSTRIAMICROSYSTEMS AG ]
