Under-Voltage Lockout (UVLO)

The TPQ05100x has an under-voltage lockout feature that stops the operation of the converter when the input voltage is

below the UVLO threshold. When the input voltage rises above the threshold with hystereis, the device starts to resume

operation.

Device Enable

The TPQ05100x enters the disable mode when the EN voltage is at a low state; the device is enabled when EN is pulled

high. When the device is disabled, the output is completely disconnected with the input.

Soft Start

The TPQ05100x enters the soft start mode when EN rises above the threshold with the soft start feature. The output voltage

gradually rises with the reduced output current limit within the first 500 μs. When the output voltage reaches the target value,

the device automatically enters normal operation.

Over-Current Protection (OCP)

The TPQ05100x has a cycle-by-cycle over-current protection feature (OCP). When the device senses inductor peak current

higher than its current limit threshold ILIM, the device will turn off its power FET to prevent further increase of the inductor

current. The output voltage will drop accordingly. If the output voltage drops below the input voltage, the device enters the

down mode. When the output voltage further drops to below 2.3 V, the device will start up again. The OCP feature is not

enabled during pass-through mode operation.

Output Short to Ground Protection

The TPQ05100x has output short to ground protection when the output voltage is below 2.3 V, and limits switching current to

200 mA. Once the output voltage rises above 2.3 V, the device will go back to the soft start mode and normal operation.

Over-Voltage Protection (OVP)

The TPQ05100x has over-voltage protection to prevent output from damage. When the output voltage exceeds the over-

voltage protection threshold, the device stops power FET switching. When the output voltage falls below the falling threshold,

the device starts to switch again.

Down Mode Regulation

The TPQ05100x enters the down-mode operation when the output voltage target is set below the input voltage, VIN > VOUT –

50 mV. The power PFET gate will be pulled to the input voltage. During down mode operation, the voltage across the power

PFET will be significantly higher than normal operation, thus the thermal effect must be taken into consideration to prevent

the device from overheating. It will get back to boost operation when the input voltage is 100-mV below the output voltage.

Pass-Through Operation

The TPQ05100x enters pass-through operation when VIN > VOUT + 0.5 V, and turns on the power PFET completely. The

output voltage is determined by the input voltage minus voltage drop across the power FET, which equals to the output

current times on-resistance of the power PFET and inductor DC resistance. When the input voltage falls below the target

output voltage + 150 mV, the device exits the pass-through mode and enters the down mode.

Over-Temperature Protection (OTP)

The TPQ05100x will shut down the device when the junction temperature rises above the over-temperature protection rising

threshold. When the junction temperature falls below the over-temperature falling threshold, the device starts operation.

TPQ05100x

0.9-V to 5.5-V VIN, 600-mA Synchronous Step-up Regulator

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