HT77xxSA数据手册Holtek中文资料规格书

描述 Description

The HT77xxSA devices are a high efficiency PFM synchronous 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 voltage 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 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.

 

特性 Features

• Low start-up voltage: 0.7V (Typ.)
• High efficiency: 2.7V ≤ VOUT ≤ 5.0V upper 90% (Typ.)
• High output voltage accuracy: ±2.5%
• Output voltage: 2.7V, 3.0V, 3.3V, 5.0V
• Output current up to 200mA
• Ultra low supply current IDD: 5µA (Typ.)
• Low ripple and low noise
• Low shutdown current: 0.1µA (Typ.)
• 3-pin SOT89, 3-pin SOT23 and 5-pin SOT23 package