Datasheet

TPS60300, TPS60301, TPS60302, TPS60303
SINGLE-CELL TO 3.0-V/3.3-V, 20-mA DUAL OUTPUT,
HIGH-EFFICIENCY CHARGE PUMP
SLVS302A – DECEMBER 2000 – REVISED MARCH 2001
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
detailed description
operating principle
The TPS6030x charge pumps are voltage quadruplers that provide a regulated 3.3-V or 3.0-V output from a
0.9-V to 1.8-V input. They deliver a maximum load current of 20 mA. Designed specifically for space critical
battery powered applications, the complete converter requires only five external capacitors and enables the
design to use low-cost, small-sized, 1-µF ceramic capacitors. The TPS6030x circuits consist of an oscillator,
a voltage reference, an internal resistive feedback circuit, an error amplifier, two charge pump stages with
MOSFET switches, a shutdown/start-up circuit, and a control circuit.
shutdown
Driving EN low disables the converter. This disables all internal circuits, reducing input current to only 0.05 µA.
Leakage current drawn from the output pins OUT1 and OUT2 is a maximum of 1 µA. The device exits shutdown
once EN is set high (see start-up procedure described below). The typical no-load, start-up time is 400 µs. When
the device is disabled, the load is isolated from the input. This is an important feature in battery operated
products because it extends the battery shelf life.
start-up procedure
The device is enabled when EN is set from logic low to logic high. CP1 will first enter a dc start-up mode during
which the capacitor on OUT1 is charged up to about V
IN
. After that, it starts switching to boost the voltage further
up to about two times V
IN
. CP2 will then follow and charge up the capacitor on OUT2 to about the voltage on
OUT1, after that, it will also start switching and boost up the voltage to its nominal value. EN must not exceed
the highest voltage applied to the device.
NOTE:
During start-up with V
OUT
= 0 V, the highest voltage is the input voltage.
power-good detector
The power-good output is an open-drain output on the TPS60300 and TPS60301 or a push-pull output on the
TPS60302 and TPS60303. The PG-output pulls low when the output of OUT2 is out of regulation. When the
output rises to within 98% of regulation, the power-good output goes active high. In shutdown, power-good is
pulled low. In normal operation, an external pullup resistor with the TPS60300 and TPS60301 is typically used
to connect the PG pin to VOUT. The resistor should be in the 100-kΩ to 1-MΩ range. If the PG output is not used,
it should remain unconnected. Output current at PG (TPS60302, TPS60303) will reduce maximum output
current at OUT2.