TC1682 Datasheet, PDF (1/10 Pages) Microchip Technology – Inverting Charge Pump Voltage Doublers with Active High Shutdown

M ^{TC1682/TC1683/TC1684}
Inverting Charge Pump Voltage Doublers with Active High Shutdown
Features
• Small 8-Pin MSOP Package
• Operates from 1.8V to 5.5V
• 120 Ohms (typ) Output Resistance
• 99% Voltage Conversion Efficiency
• Only 3 External Capacitors Required
• Power-Saving Shutdown Mode
• Low Active Supply Current
- 95µA (typ) for TC1682
- 225µA (typ) for TC1683
- 700µA (typ) for TC1684
• Fully Compatible with 1.8V Logic Systems
Applications
• LCD Panel Bias
• Cellular Phones PA Bias
• Pagers
• PDAs, Portable Data Loggers
• Battery-Powered Devices
Device Selection Table
Part
Number
TC1682EUA
TC1683EUA
TC1684EUA
Package
8-Pin MSOP
8-Pin MSOP
8-Pin MSOP
Osc.
Freq.
(kHz)
Operating
Temp.
Range
12 -40°C to +85°C
35 -40°C to +85°C
125 -40°C to +85°C
Package Type
8-Pin MSOP
C1– 1
C2+ 2
C2– 3
V_{OUT 4}
TC1682
TC1683
TC1684
8 SHDN
7 C1+
6 V_IN
5 GND
General Description
The TC1682/TC1683/TC1684 are CMOS charge pump
converters that provide an inverted doubled output
from a single positive supply. An on-board oscillator
provides the clock and only three external capacitors
are required for full circuit implementation. Switching
frequencies are 12kHz for the TC1682, 35kHz for the
TC1683, and 125kHz for the TC1684. When the SHDN
pin is held at a logic high, the device goes into a very
low power mode of operation consuming less than 1µA
(typ) of supply current.
Low output source impedance (typically 120Ω),
provides output current up to 10mA. The TC1682/
TC1683/TC1684 feature a 1.8V to 5.5V operating
voltage range and high efficiency, which make them an
ideal choice for a wide variety of applications requiring
a negative doubled voltage derived from a single
positive supply (for example: generation of -7.2V from
a +3.6V lithium cell or -10V generated from a +5V logic
supply).
The minimum external part count, small physical size
and shutdown mode feature make this family of
products useful for a wide variety of negative bias
power supply applications.
Functional Block Diagram
+
C1+
V_IN
C1
C1–
SHDN
C2+ TC1682
+
TC1683
C2
C2– ^TC1684
Input
OFF
ON
GND
V_OUT
V_OUT = -(2 x V_IN)
– _COUT
+
C1 must have a voltage rating ≥ V_IN
C2 and C_OUT must have a voltage rating ≥ 2V_IN
 2002 Microchip Technology Inc.
DS21537B-page 1