The TPS65200 integrates a high-efficiency, USB-friendly switch-mode charger with OTG support for single-cell Li-ion and Li-polymer batteries, D+D- detection, a 50-mA fixed-voltage LDO, a high-efficiency WLED boost converter, and high-accuracy current-shunt monitor into a single chip.
The charger features a synchronous 3-MHz PWM controller with integrated power MOSFETs, input current sensing and regulation, input-voltage dynamic power management, high-accuracy charge current and voltage regulation, and charge termination. It charges the battery in three phases: low-current pre-charge, constant current fast-charge, and constant voltage trickle-charge. The input current is automatically limited to the value set by the host. The charger can be configured to terminate charge based on user-selectable minimum current level and to automatically restart the charge cycle if the battery voltage falls below the recharge threshold. A safety timer with reset control provides a safety backup for I2C interface. The charger automatically enters sleep mode or high impedance mode when the input supply is removed. The charge status is reported to the host using the I2C interface and STAT pin. The D+D- detection circuit allows automatic detection of a USB wall-charger. If a wall-charger is detected the input current limit is automatically increased from 500 mA to 975 mA.
In OTG mode the PWM controller boosts the battery voltage to 5 V and provides up to 200-mA of current to the USB output. At very light loads the boost operates in burst mode to optimize efficiency. OTG mode can be enabled either through I2C interface or GPIO control.
The TPS65200 also provides a WLED boost converter with integrated 40-V switch FET, that drives up to 10 WLEDs in series. The boost converter runs at 600-kHz fixed switching frequency to reduce output ripple, improve conversion efficiency, and allows for the use of small external components. The default WLED current is set with a sense resistor, and the feedback voltage is regulated to 200 mV, as shown in the typical application. For brightness dimming, the feedback voltage can be changed through the I2C interface or by application of a PWM signal to the CTRL pin. In the latter case the feedback voltage is regulated down proportional to the PWM duty cycle (analog dimming) rather than pulsing the LED current to avoid audible noise on the output capacitor. For maximum protection, the device features integrated open LED protection that disables the TPS65200 to prevent the output from exceeding the absolute maximum ratings during open LED conditions.
A fixed-gain, high-accuracy current shunt monitor senses the voltage drop across an external, 20-mΩ sense resistor and provides an analog output voltage that is proportional to the charge/discharge current of the battery. The sense voltage is amplified by a factor of 25 and offset by VZERO, an externally provided reference voltage. VZERO is internally buffered to avoid loading of the reference source.
The TPS65200 comes in a tiny, 2.8-mm × 2.6-mm, 36-ball, 0.4-mm pitch die size ball grid array (DSBGA) or a 6-mm × 6-mm, 0.5-mm pitch QFN.
Battery Switching Charger, WLED Driver, and Current Shunt Monitor in a Single Package
Charges Faster Than Linear Chargers
High-Accuracy Voltage and Current Regulation
Input Current Regulation Accuracy: ±5% (100 mA, 500 mA)
Charge Voltage Regulation Accuracy: ±0.5% (25°C), ±1% (0 – 125°C)
Charge Current Regulation Accuracy: ±5%
Input Voltage Based Dynamic Power Management
Bad Adaptor Detection and Rejection
Safety Limit Register for Maximum Charge Voltage and Current Limiting
High-Efficiency Mini-USB/AC Battery Charger for Single-Cell Li-Ion and Li-Polymer Battery Packs
20-V Absolute Maximum Input Voltage Rating
6.0-V Maximum Operating Input Voltage
Built-In Input Current Sensing and Limiting
Integrated Power FETs for Up to 1.25-A Charge Rate
Programmable Charge Parameters through I2C Interface (up to 400 Kbps):
Charge Voltage (3.5 V - 4.44 V)
Synchronous Fixed-Frequency PWM Controller Operating at 3 MHz With 0% to 99.5% Duty Cycle
Automatic High Impedance Mode for Low Power Consumption