2002 Microchip Technology Inc. DS21367B-page 1
M
TC1221/TC1222
Features
• Charge Pumps in 6-Pin SOT-23A Package
• 96% Voltage Conversion Efficiency
• Voltage Inversion and/or Doubling
• Operates from +1.8V to +5.5V
• Up to 25mA Output Current
• Only Two External Capacitors Required
• Power-Saving Shutdown Mode
• Fully Compatible with 1.8V Logic Systems
Applications
• LCD Panel Bias
• Cellular Phones
• Pagers
• PDAs, Portable Data Loggers
• Battery-Powered Devices
Device Selection Table
Package Type
General Description
The TC1221/TC1222 are CMOS “charge-pump”
voltage converters in ultra-small 6-Pin SOT-23A
packages. They invert and/or double an input voltage
which can range from +1.8V to +5.5V. Conversion
efficiency is typically 96%. Switching frequency is
125kHz for the TC1221, 750kHz for the TC1222. When
the shutdown pin is held at a logic low, the device goes
into a very low power mode of operation, consuming
less than 1µA of supply current.
For standard voltage inverter applications, the device
requires only two external capacitors. With a few
additional components a positive doubler can also be
built. All other circuitry, including control, oscillator,
power MOSFETs are integrated on-chip. Typical supply
currents are 290µA (TC1221) and 1800µA (TC1222).
All devices are available in 6-pin SOT-23A surface
mount packages.
Functional Block Diagram
Part
Number
Package
Osc.
Freq.
(kHz)
Operating
Temp.
Range
TC1221ECH 6-Pin SOT-23A 125 -40°C to +85°C
TC1222ECH 6-Pin SOT-23A 750 -40°C to +85°C
C
+
C
–
TC1221ECH
TC1222ECH
123
54
V
IN
SHDN
GND
6-Pin SOT-23A
NOTE: 6-Pin SOT-23A is equivalent to the EIAJ SC-74
OUT
6
TC1221
TC1222
V
IN
V
–
Output
C
+
C
–
C1
C2
Input
GND
OUT
SHDN
ON
OFF
+
+
Negative Voltage Inverter
High Frequency Switched Capacitor Voltage Converters
with Shutdown in SOT Packages
