XC9801/02 Series
Block Diagram
C1+
Step-Up Charge Pump ICs
C1-
VIN
N5
P1
P2
VOUT
N4
CE
Chip
Enable
P3
SENSE
Oscillator
Controler
Vref
GND
PGND
(1) Basic Operations
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
(2) Stand-by Function
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.
(3) PFM (Pulse Skip) Operations
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.
Absolute Maximum Ratings
Ta = 25
O
C, GND = 0V
PARAMETER
V
IN
pin voltage
V
OUT
pin voltage
C1 + pin voltage
C1 - pin voltage
CE pin voltage
V
OUT
pin output current
Power dissipation
MSOP-8A
USP-8
SYMBOL
V
IN
V
OUT
C1+
C1-
V
CE
I
OUT
Pd
Topr
Tstg
Operating Temperature
Storage Temperature
CONDITIONS
-0.3
~
6
-0.3
~
12
-0.3
~
VOUT + 0.3
-0.3
~
VOUT + 0.3
-0.3
~
VIN + 0.3
200
150
TBD
- 40
~
+ 85
- 40
~
+ 125
UNITS
V
V
V
V
V
mA
mW
O
O
C
C
2
TOREX [ TOREX SEMICONDUCTOR ]
