HV9912NG微芯LED大功率驱动

Features

• Switch-mode Controller for Single-switch Drivers:

- Buck

- Boost

- Buck-boost

- SEPIC

• Works with High-side Current Sensors

• Closed-loop Control of Output Current

• High Pulse-Width Modulation (PWM) Dimming

Ratio

• Internal 90V Linear Regulator (can be extended

using external Zener Diodes)

• Internal 2% Voltage Reference (0°C < TA < 85°C)

• Constant Frequency or Constant Off-time

Operation

• Programmable Slope Compensation

• Linear and PWM Dimming

• +0.2A/–0.4A Gate Driver

• Hiccup Mode Protection for both Short-circuit and

Open-circuit Conditions

• Output Overvoltage Protection

• Synchronization Capability

• Pin Compatible with HV9911

General Description

HV9912 is an LED driver IC designed to control

single-switch PWM converters (buck, boost,

buck-boost and SEPIC) in a Constant Frequency or

Constant Off-time mode. The controller uses a peak

Current Mode control scheme with programmable

slope compensation and includes an internal

transconductance amplifier to control the output current

in closed loop, enabling high output current accuracy.

In the case of buck and buck-boost converters, the

output current can be sensed using a high-side current

sensor like the HV7800. In the Constant Frequency

mode, multiple HV9912 ICs can be synchronized with

each other or with an external clock, using the SYNC

pin. Programmable MOSFET current limit enables

current limiting during Input Undervoltage and Output

Overload conditions. The IC also includes a 0.2A

source and 0.4A sink gate driver that makes the

HV9912 suitable for high-power applications. An

internal 90V linear regulator powers the IC, eliminating

the need for a separate power supply for the IC. The IC

also provides a FAULT output, which can be used to

disconnect the LEDs in case of a Fault condition using

an external disconnect FET. HV9912 also provides a

TTL-compatible, low-frequency PWM dimming input

that can accept an external control signal with a duty

ratio of 0-100% and a frequency of up to a few kilohertz.

The HV9912 includes hiccup protection from both short

and open circuits, with automatic recovery after the

Fault condition is cleared.