TI 公司的TPS65137 是有源矩陣 OLED (AMOLED)電源解決方案,,包括一個采用LDO作為后穩(wěn)壓器的升壓轉(zhuǎn)換器,輸入電壓從2.3V到5.5V,具有極好的線瞬態(tài)穩(wěn)壓功能,,輸出電壓精度1%,,低噪音,輸出電流200mA,,固定4.6V正輸出電壓,,數(shù)字可編程負(fù)輸出電壓可低至-5.2V,具有短路保護和熱關(guān)斷,,主要用在有源矩陣 OLED(AMOLED),。本文介紹了TPS65137主要特性,方框圖以及典型應(yīng)用電路,。
The TPS65137 consists of a boost converter using a LDO as post regulator. The output voltage of the boost converter is regulated to operate the internal LDO above its dropout voltage maintaining best line and load regulation of OUTP. The internal LDO disconnects OUTP during shutdown and allows regulation of the output when the input voltage is higher than OUTP. The LDO minimizes the output voltage ripple of OUTP. The negative output uses a buck boost converter topology operating in DCM (Discontinuous Conduction Mode) providing superior line regulation. In order to adjust the output voltage of the negative converter a digital interface can be used to program the output voltage. To achieve high efficiency over the entire load current range the device reduces the switching frequency with the load current using its internal voltage controlled oscillator (VCO). Since the boost converter output CB is post regulated by the integrated LDO (Low Dropout Regulator) the output voltage ripple is minimized and the line transient response is at its best. Because of this topology the operation mode of the boost converter has minimum effect on the output voltage ripple observed on OUTP. The boost converter, as well as the negative converter operate in peak current mode using the VCO (Voltage Controlled Oscillator) while operating in DCM (Discontinuous Conduction Mode). When entering CCM (Continuous Conduction Mode) the converter operates in peak current control using fixed off time control.
TPS65137主要特性:
2.3 V to 5.5 V Input Voltage Range
1% Output Voltage Accuracy Vpos
Excellent Line Transient Regulation
Low Noise Operation
200 mA Output Current
Fixed 4.6 V Positive Output Voltage
Digitally Programmable Negative Output Voltage Down to –5.2V
–4.9V Default Value for Vneg
Advanced Power Save Mode
Short Circuit Protection
Thermal Shutdown
TPS65137A High impedance output in shutdown
3×3 mm 10 Pin QFN Package
TPS65137應(yīng)用:
Active Matrix OLED Power Supply
圖1,。TPS65137功能方框圖
圖2。TPS65137典型應(yīng)用電路圖
詳情請見:
http://focus.ti.com/lit/ds/symlink/tps65137.pdf