U6084B_05 Datasheet, PDF (1/11 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
1. 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.
PWM Power
Control with
Automatic
Duty-cycle
Reduction
U6084B
Figure 1-1. 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
150 Ω
R₃
Ground
.
Rev. 4677C–AUTO–09/05