1 Features

• Predriver for Single-Phase Full-Wave Drive

– PNP-NMOS is Used as an External Power TR,

Enabling High-Efficiency Low-Consumption

Drive by Means of the Low-Saturation Output

and Single-Phase Full-Wave Drive (PMOS-

NMOS Also Applicable)

• External PWM Input Enabling Variable Speed

Control

– Separately-Excited Upper Direct PWM (f = 25

kHz) Control Method, Enabling Highly Silent

Speed Control

• Compatible with 12-V, 24-V, and 48-V Power

Supplies

• Current Limiter Circuit Incorporated

– Chopper Type Current Limit at Start

• Reactive Current Cut Circuit Incorporated

– Reactive Current Before Phase Change is Cut

to Enable Silent and Low-Consumption Drive

• Minimum Speed Setting Pin

– Minimum Speed Can Be Set With External

Resistor. Start Assistance Circuit Enables Start

at Extremely Low Speed.

• Constant-Voltage Output Pin for Hall Bias

• Lock Protection and Automatic Reset Functions

Incorporated

• FG (Rotation Speed Detection) and RD (Lock

Detection) Output

2 Applications

• Server Fans (Up to 48 V)

• Appliance Fans (Up to 48 V)

3 Description

The TMP814 is a single-phase bipolar variable speed

fan motor predriver that works with an external PWM

signal. A highly efficient, quiet and low-power

consumption motor driver circuit, with a large variable speed, can be implemented by adding a small

number of external components.

This device is optimal for driving large scale fan

motors (with large air volume and large current) such

as those used in servers and consumer products.