HT7727SA Datasheet, PDF (1/17 Pages) Holtek Semiconductor Inc – 200mA PFM Synchronous Step-up DC/DC Converter

HT77xxSA
200mA PFM Synchronous
Step-up DC/DC Converter
Features
• Low start-up voltage: 0.7V (Typ.)
• High efficiency: 2.7V ≤ V_OUT ≤ 5.0V upper 90%
(Typ.)
• High output voltage accuracy: ±2.5%
• Output voltage: 2.7V, 3.0V, 3.3V, 3.7V, 5.0V
• Output current up to 200mA
• Ultra low supply current I_DD: 5μA (Typ.)
• Low ripple and low noise
• Low shutdown current: 0.1μA (Typ.)
• TO92, SOT89, SOT23 and SOT23-5 package
Applications
• Palmtops/PDAs
• Portable communicators/Smartphones
• Cameras/Camcorders
• Battery-powered equipment
General Description
The HT77xxSA devices are a high efficiency PFM syn-
chronous step-up DC-DC converter series which are
designed to operate with both wire wound chip power
inductors and also with multi-layered chip power
inductors. The device series have the advantages of
extremely low start-up voltage as well as high output
voltage accuracy. Being manufactured using CMOS
technology ensures ultra low supply current. Because
of their higher operating frequency, up to 500 kHz, the
devices have the benefits of requiring smaller outline
type lower value external inductors and capacitors. The
higher operating frequency also offers the advantages
of much reduced audio frequency noise. The devices
require only three external components to provide a
fixed output voltage of 2.7V, 3.0V, 3.3V, 3.7V or 5.0V.
The HT77xxSA devices include an internal oscillator,
PFM control circuit, driver transistor, reference volt-
age unit and a high speed comparator. They employ
pulse frequency modulation techniques, to obtain
minimum supply current and ripple at light output
loading. These devices are available in space saving
TO92, SOT89, SOT23 and SOT23-5 packages. For
SOT23-5 package types, they also include an internal
chip enable function to reduce power consumption
when in the shutdown mode.
Selection Table
Part No.
HT7727SA
HT7730SA
HT7733SA
HT7737SA
HT7750SA
Output Voltage
2.7V
3.0V
3.3V
3.7V
5.0V
Note:″xx″ stands for output voltages.
Package
TO92
SOT89
SOT23
SOT23-5
Marking
HT77xxSA (for TO92)
77xxSA (for SOT89)
xxSA (for SOT23)
xxSA (for SOT23-5)
Rev. 1.50
1
June 25, 2016