Diodes Incorporated AM9800GSTR-G1

Overview

AM9800GSTR-G1 from BCD Semiconductor Manufacturing Limited is a three-phase sensorless brushless DC motor driver IC with direct PWM control, integrated lock protection, thermal shutdown, and forward/reverse rotation selection. It operates from 2.2–6 V, delivers up to 0.7 A output current, features soft-switched drive for acoustic noise reduction, and consumes only 20 µA in PWM=0 stopped state. It targets CPU cooler fans in notebook PCs.

For engineers reviewing the AM9800GSTR-G1 datasheet, AM9800GSTR-G1 pinout, AM9800GSTR-G1 application, or AM9800GSTR-G1 equivalent, key selection criteria include its SSOP-16 package, built-in current limiting (V_RF = 0.25 V), 25 kHz PWM input support, FG tachometer output, and thermal shutdown at 175°C with 25°C hysteresis.

Technical Context

The AM9800GSTR-G1 implements sensorless commutation using back-EMF detection via COMIN/FIL pins with external RC filtering, enabling rotor position estimation without Hall sensors. Its internal charge pump (VG, CP, CPC pins) generates ~9.7 V gate drive for high-side N-channel MOSFETs, supporting synchronous rectification.

It integrates a programmable OSC circuit (f_OSC = 1.0 kHz with 2200 pF), lock detection with configurable t_ON = 2 s / t_OFF = 4 s, and soft-switching PWM modulation to reduce dv/dt-induced acoustic noise. The F/R pin selects rotation direction by altering phase energization sequence (U→V→W vs. U→W→V).

Key Specifications

Pinout & Package

AM9800GSTR-G1 is housed in a 16-pin SSOP (Shrink Small Outline Package) with 0.635 mm pitch, 3.8 mm × 4.7 mm body size, and exposed thermal pad (non-electrical). The package supports surface-mount reflow assembly and provides adequate thermal dissipation for <0.8 W power handling on standard PCBs.

Key Features

Applications

Availability

AM9800GSTR-G1 is available at Aetrix Electronics and suitable for CPU cooler fan control, embedded thermal management, server chassis fan modules, and automotive cabin air circulation requiring stable component supply and RoHS-compliant green packaging.

Supply support for AM9800GSTR-G1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and mixed-signal IC designer and foundry partner, specializing in power management, motor control, and high-voltage process technologies since 2003.

The AM9800 belongs to BCD's BLDC motor driver product line, engineered specifically for cost-sensitive, low-noise, sensorless cooling applications in computing and consumer electronics.

FAQ

What is the function of the COMIN and FIL pins?

COMIN receives the motor's back-EMF signal from the center tap (COM), while FIL connects to an external capacitor that forms a low-pass filter with COMIN. This RC network suppresses high-frequency switching noise, enabling accurate zero-crossing detection for sensorless commutation. A 1000–10000 pF capacitor is required between COMIN and FIL per the datasheet.

How does the AM9800GSTR-G1 implement forward/reverse control?

Forward/reverse rotation is selected by the logic level on pin 9 (F/R): low (≤0.2×VCC) enables forward rotation (U→V→W phase sequence), and high (≥0.8×VCC) enables reverse (U→W→V). The internal pull-down resistor ensures default forward operation if F/R is left open, but switching must occur only when the motor is fully stopped to prevent torque disruption.

What external components are mandatory for basic operation?

Four external components are mandatory: (1) a 2200 pF capacitor from OSC (pin 7) to SGND for startup timing; (2) a 1 µF capacitor from CPC (pin 14) to SGND for charge pump stability; (3) a resistor from RF (pin 15) to SGND to set current limit (e.g., 1 Ω for 0.25 A); and (4) a 10 kΩ pull-up resistor from FG (pin 10) to VCC for tachometer output.

Is AM9800GSTR-G1 still in active production?

No - the datasheet explicitly states "PART OBSOLETE – NO ALTERNATE PART" and "PART DISCONTINUED". While Aetrix Electronics maintains legacy inventory for design continuity and repair, no new production lots are being manufactured, and no official pin-compatible or functional replacement has been designated by BCD Semiconductor.