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

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

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:

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-k

Ω 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.