Block Diagram

(1) Basic Operations

(2) Stand-by Function

(3) PFM (Pulse Skip) Operations

Absolute Maximum Ratings

MSOP-8A

USP-8

2

TBD

mW

Power dissipation

Pd

When the voltage at CE (chip enable) is ‘low’ (0V), P1,P2 & P3 will be OFF with N4 & N5 ON. The external capacitor

C1 will discharge and impedance at Vout will be high.

Whilst maintaining output voltage, the XC9802 provides the added security of protection against drops in efficiency

during light loads as a result of the pulse, generated by the internal oscillator, being skipped and the operating

frequency being changed.

Using the XC9801/02’s clock generated by the internal oscillator, a step-up charge pump operation can be brought

about as a result of the alternate switching between operating conditions where P1 & N4 are ON with P2 & P3 OFF

(or) P1 & N4 are OFF with P2 & P3 ON. By connecting the SENSE pin to VOUT, output voltage can be fedback and

the difference between the feedback voltage and the reference voltage (Vref) are compared by the internal operational

amplifier. Output voltage can be stabilized (Note 2) by controlling P3’s gate voltage waveform via the signal generated

by the internal amplifier.

Please note that this stabilizing function will not operate with VIN < (VOUT/2) or VIN

≥ VOUT.

By connecting SENSE to ground, the output stability function, as described above, can be halted and the IC can be

used as a step-up doubler.

Note 2 : As a result of P3 gradually reaching an ON state with each clock (signal), rush current is controlled, the ripple

decreases and with the combination of the independent phase compensation circuit, output voltage is stabilized

- 40

- 40

UNITS

V

V

V

V

V

mA

CONDITIONS

-0.3

-0.3

-0.3

Operating Temperature

Storage Temperature

Topr

Tstg

C1 - pin voltage

CE pin voltage

-0.3

-0.3

200

150

PARAMETER

C1 + pin voltage

XC9801/02 Series

Step-Up Charge Pump ICs

SYMBOL

C1+

C1-

VIN

CE

C1+

C1-

VOUT

SENSE

GND

PGND

Chip

Enable

Oscillator

Vref

Controler

P1

P2

P3

N4

N5