HT77XX
PFM Asynchronous Step-up DC to DC Converter (100mA)
Features
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Low start-up voltage: 0.7V (Typ.), 0.9V (Max.)
High efficiency: 85% (Typ.), VOUT³2.7V
High output voltage accuracy: ±2.5%
Output current up to 100mA
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Ultra low supply current IDD2: 4mA (Typ.)
Low ripple and low noise
Output voltage: 1.8V, 2.2V, 2.7V, 3.0V, 3.3V, 3.7V,
5.0V
Low shutdown current: 0.5mA (Typ.)
TO92, SOT89, SOT23 and SOT23-5 package
Applications
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Palmtops/PDAs
Cameras/Camcorders
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Portable communicators/Smartphones
Battery-powered equipment
General Description
The HT77XX series is a set of PFM step-up DC/DC con-
verter with high efficiency and low ripple. The series fea-
tures extremely low start-up voltage and high output
voltage accuracy. They require only three external com-
ponents to provide a fixed output voltage of 1.8V, 2.2V,
2.7V, 3.0V, 3.3V, 3.7V or 5.0V. CMOS technology en-
sures ultra low supply current and makes them ideal for
battery-operated applications powered from one or
more cells.
The HT77XX consists of an oscillator, a PFM control cir-
cuit, a driver transistor, a reference voltage unit, and a
high speed comparator. They employ pulse frequency
modulation (PFM) for minimum supply current and rip-
ple at light output loading. These devices are available
in space saving TO92, SOT89, SOT23 and SOT23-5
packages. For SOT23-5 package, it also build-in a chip
enable function to reduce power consumption during
shutdown mode.
Selection Table
Part No.
HT7718
HT7722
HT7727
HT7730
HT7733
HT7737
HT7750
Output Voltage
1.8V
Package
Marking
2.2V
HT77XX (for TO92)
HT77XX# (for SOT89)
HT77XX+ (for SOT89)
77XX# (for SOT23)
77XX+ (for SOT23)
77XX# (for SOT23-5)
77XX+ (for SOT23-5)
2.7V
TO92
SOT89
SOT23
SOT23-5
3.0V
3.3V
3.7V
5.0V
Note:
²XX² stands for output voltages.
Both lead free and green compound devices are available.
²#² stands for lead free devices. For the TO-92 package, there will be a ²#² mark at the end of the date code.
²+² stands for green compound devices, which are Lead-free and Halogen-free.
For the TO-92 package, there will be a ²+² mark at the end of the date code.
Rev 1.90
1
October 13, 2010