Datasheet

TPS60310, TPS60311, TPS60312, TPS60313
SINGLE-CELL TO 3-V/3.3-V, 20-mA DUAL OUTPUT,
HIGH-EFFICIENCY CHARGE PUMP WITH SNOOZE MODE
SLVS362A – MAY 2001 – REVISED AUGUST 2001
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
detailed description
operating principle
The TPS6031X charge pumps are voltage quadruplers that provide a regulated 3.3-V or 3-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 TPS6031X circuits consist of an oscillator, a voltage
reference, an internal resistive feedback circuit, two error amplifiers, two charge pump stages with MOSFET
switches, a shutdown/start-up circuit, and a control circuit.
snooze mode
The devices contain a circuit which dramatically reduces the quiescent current at light loads. This so called
snooze mode must be enabled by pulling the SNOOZE
pin low. When the output current decreases below the
snooze mode threshold, the device enters the snooze mode. In snooze mode, the main error amplifier with 4%
error and 50-µA supply current is disabled and a 10%, 2-µA regulator controls the output voltage.
start-up procedure
The start-up performance of the device is independent of the level of the snooze input. When voltage is applied
to the input, 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
. CP1 first enters a dc
start-up mode during which the capacitor on OUT1 is charged up to about V
IN
. CP2 then follows and charges
up the capacitor on OUT2 to about the voltage on OUT1, after that, it also starts switching and boosts up the
voltage to its nominal value. The voltage at the SNOOZE
pin 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 TPS60310 and TPS60311 or a push-pull output on the
TPS60312 and TPS60313. 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 TPS60310 and TPS60311 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 (TPS60312, TPS60313) reduces maximum output current
at OUT2.
In snooze mode, the output voltage is sampled at a rate up to 2 ms and is applied to the power-good comparator.
In normal mode, the output voltage is measured continuously.