本文介紹了AS3676主要特性, 應(yīng)用方框圖, 模擬LDO方框圖, 升壓DC/DC轉(zhuǎn)換器方框圖, 環(huán)境光傳感器內(nèi)部電路圖以及LED功能測(cè)試電路圖, 自動(dòng)控制LED內(nèi)部電路圖和外接元件列表.
Aaustriamicrosystems公司的 AS3676 是高度集成的CMOS功率和照明管理單元,適嗯移動(dòng)手機(jī)或其它以一節(jié)鋰離子電池或3節(jié)NiMH 電池供電的設(shè)備.它集成了一個(gè)用于白背景光LED的升壓DC/DC轉(zhuǎn)換器,一個(gè)大功率電荷泵,一個(gè)ADC,13個(gè)電流沉,LED功能測(cè)試,一個(gè)兩線串行接口和控制邏輯.
AS3676主要特性:
High-Efficiency Step Up DC/DC Converter
- Up to 26V/50mA for White LEDs
- Programmable Output Voltage with External Resistors and Serial Interface
- Over voltage Protection
High-Efficiency High-Power Charge Pump
- 1:1, 1:1.5, and 1:2 Mode
- Automatic Up Switching (can be disabled and 1:2 mode can be blocked)
- Output Current up to 400mA/500mA pulsed
- Efficiency up to 95%
- Very Low effective Resistance (2.5Ω typ. in 1:1.5)
- Only 4 External Capacitors Required:
2 x 1μF Flying Capacitors, 2 x 2.2μF Input/Output Capacitors
- Supports LCD White Backlight LEDs, or RGB LEDs
13 Current Sinks
- All 13 current sinks fully Programmable (8-bit) from: 0.15mA to 38.5mA (up to 75.6mA for
CURR30...CURR33)
- Three current sinks are High Voltage capable (CURR1, CURR2, CURR6)
- Programmable Hardware Control (Strobe, and Preview or PWM)
- Selectively Enable/Disable Current Sinks
- Dynamic Luminance Scaling (DLS) support to improve backlight operating time (can adjust any current source)
- Light Sensor input with internal hardware processing to control backlight according to ambient light using 3 groups - any current source can select one of the groups or no light sensor control
Internal PWM Generation
- 8 Bit resolution
- Autonomous Logarithmic up/down dimming
Led Pattern Generator
- Autonomous driving for Fun RGB LEDs
- Support indicator LEDs
10-bit Successive Approximation ADC
- 27μs Conversion Time
- Selectable Inputs: VANA/GPI, GPIO1/DLS, GPIO2/LIGHT, all current sources, VBAT, CPOUT, DCDC_FB
- Internal Temp. Measurement
- Light Sensor input with Java support (JSR-256): read ADC processed value
Support for automatic LED testing (open and shorted LEDs can be identified)
Strobe Timeout protection
- Up to 1600ms
- Three different timing modes
Two General Purpose Inputs/Output
- GPIO1/DLS, GPIO2/LIGHT
- Digital Input, Digital Output using VANA/GPI supply and Tristate
- GPIOs Programmable Pull-Up/Down
Programmable LDO
- 1.8 to 3.35V, 150mA
- Programmable via Serial Interface
Standby LDO always on
- Regulated 2.5V max. output 10mA
- 3μA Quiescent Current
Audio can be used to drive RGB LED(s)
- Color and Brightness depends on audio amplitude
Wide Battery Supply Range: 3.0 to 5.5V
Two Wire Serial Interface Control
Over current and Thermal Protection
WL-CSP30 3x2.5mm, 0.5mm pitch Package
AS3676應(yīng)用:
Power- and lighting-management for mobile telephones and other 1-cell Li+ or 3-cell NiMH powered devices.
圖1.AS3676方框圖
圖2.AS3676模擬LDO方框圖
圖3.AS3676升壓DC/DC轉(zhuǎn)換器方框圖:電流反饋和過(guò)壓保護(hù)
圖4.AS3676升壓DC/DC轉(zhuǎn)換器詳細(xì)方框圖
圖5.AS3676環(huán)境光傳感器內(nèi)部電路圖
圖6.AS3676 GPIO和VANA/GPI方框圖
圖7.AS3676 LED功能測(cè)試電路圖
圖8.AS3676自動(dòng)控制LED內(nèi)部電路圖
外接元件列表:
