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.
Figure 1-1. Block Diagram with External Circuit
Current monitoring
+ short circuit detection
Output
Charge
pump
RC oscillator
Duty cycle
range
0-100%
Duty cycle
reduction
Control input
Short circuit
latch monitoring
Voltage
monitoring
Enable/
disable
9
1116
6
3
4
PWM
Logic
C
1
12
13
14
47 nF
1
150 Ω
2
5
47 kΩ
Ground
C
2
C
5
C
3
R
3
V
S
V
Batt
R
sh
PWM Power
Control with
Automatic
Duty-cycle
Reduction
U6084B
Rev. 4677C–AUTO–09/05
.
