TPS60210, TPS60211, TPS60212, TPS60213

REGULATED 3.3 V, LOW RIPPLE CHARGE PUMP

WITH ULTRALOW OPERATING CURRENT

SLVS296 − JUNE 2000

4

POST OFFICE BOX 655303

Terminal Functions

TERMINAL

I/O

DESCRIPTION

NAME

NO.

I/O

DESCRIPTION

C1+

4

Positive terminal of the flying capacitor C1

C1−

3

Negative terminal of the flying capacitor C1

C2+

6

Positive terminal of the flying capacitor C2

C2−

8

Negative terminal of the flying capacitor C2

GND

2

Ground

IN

7

I

Supply input. Bypass IN to GND with a capacitor of a minimum of 2.2

µF.

LBI/GND

1

I

Low-battery detector input for TPS60210 and TPS60212. A low-battery warning is generated at the LBO pin when

the voltage on LBI drops below the threshold of 1.18 V. Connect LBI to GND or VBAT if the low-battery detector

function is not used. For the devices TPS60211 and TPS60213, this pin is a ground (GND pin).

LBO/PG

10

O

Open-drain low-battery detector output for TPS60210 and TPS60212. This pin is pulled low if the voltage on LBI

drops below the threshold of 1.18 V. A pullup resistor should be connected between LBO and OUT or any other

logic supply rail that is lower than 3.6 V.

Open-drain power-good detector output for TPS60211 and TPS60213. As soon as the voltage on OUT reaches

about 90% of its nominal value, this pin goes active high. A pullup resistor should be connected between PG and

OUT or any other logic supply rail that is lower than 3.6 V.

OUT

5

O

Regulated 3.3-V power output. Bypass OUT to GND with the output filter capacitor Co.

SNOOZE

9

I

Three operating modes can be programmed with the SNOOZE pin.

− SNOOZE = Low programs the device in the snooze mode, enabling ultralow operating current while still

maintaining the output voltage to within 3.3 V

±6%.

− SNOOZE = High programs the device into normal operation mode where it runs from the internal oscillator.

− If an external clock signal is applied to the SNOOZE pin, the charge pump operates synchronized to the

frequency of the external clock signal.

detailed description

operating principle

The TPS6021x charge pumps provide a regulated 3.3-V output from a 1.8-V to 3.6-V input. They deliver a

minimum 100-mA load current while maintaining the output at 3.3 V

±4%. Designed specifically for space critical

battery-powered applications, the complete converter requires only four external capacitors. The device is using

the push-pull topology to achieve the lowest output voltage ripple. The converter is also optimized for a very

small board space. It makes use of small-sized capacitors, with the highest output current rating per output

capacitance.

The TPS6021x circuits consist of an oscillator, a voltage reference, an internal resistive feedback circuit, an error

amplifier, two charge-pump power stages with high-current MOSFET switches, a shutdown/start-up circuit, and

a control circuit (see functional block diagrams).

push-pull operating mode

The two single-ended charge-pump power stages operate in the push-pull operating mode (i.e., they operate

with a 180

°C phase shift). Each single-ended charge pump transfers a charge into its flying capacitor (C1 or

C2) in one-half of the period. During the other half of the period (transfer phase), the flying capacitor is placed

pump is in the charge phase, the other one is in the transfer phase. This operation ensures that there is a

continuous flow of charge to the load, hence the output capacitor no longer needs to buffer the load current for

half of the switching cycle, avoiding the high, inherent output voltage ripple of conventional charge pumps.

In order to provide a regulated output voltage of 3.3 V, the TPS6021x devices operate either in

constant-frequency linear-regulation control mode or in pulse-skip mode. The mode is automatically selected

based on the output current. If the load current is low, the controller switches into the power-saving pulse-skip

mode to boost efficiency at low output power.