U6084B Datasheet, PDF (1/10 Pages) ATMEL Corporation – PWM Power Control with Automatic Duty-cycle Reduction

Features
• Pulse-width Modulation up to 2 kHz Clock Frequency
• Protection against Short-circuit, Load-dump Overvoltage and Reverse V_S
• Duty-cycle 0 to 100% Continuously
• Output Stage for Power MOSFET
• Interference and Damage Protection According to VDE 0839 and ISO/TR 7637/1
• Charge-pump Noise Suppressed
• Ground-wire Breakage Protection
Description
The U6084B is a PWM-IC with bipolar technology designed for the control of an
N-channel power MOSFET used as a high-side switch. The IC is ideal for use in the
brightness control (dimming) of lamps such as in dashboard applications. For constant
brightness, the preselected duty-cycle can be reduced automatically as a function of
the supply voltage.
Figure 1. Block Diagram with External Circuit
V_S
16
9
Short circuit
latch monitoring
5
6
C₁
47 kΩ
RC oscillator
Control input
3
C₅
R_sh
11
Current monitoring
12
+ short circuit detection
PWM
Logic
Charge ¹³
pump
14
Output
C₂
Duty cycle
range
0-100%
Duty cycle
reduction
Voltage
monitoring
Enable/
disable
4
1
2
V_Batt
C₃
47 nF
PWM Power
Control with
Automatic
Duty-cycle
Reduction
U6084B
150 Ω
R₃
Ground
Rev. 4677B–AUTO–02/04