MIC4802 Datasheet, PDF (4/12 Pages) Micrel Semiconductor – High Efficiency 800mA Single Channel Linear WLED Driver with Ultra Fast PWM™ Control

Micrel Inc.
Typical Characteristics
LED Battery Voltage
vs. LED Current
1.4
1.2
VIN = 5.5V
1
VIN = 3.5V
0.8
VIN = 3.0V
0.6
0.4
0.2
0
5.5 5 4.5 4 3.5 3 2.5
LED BATTERY VOLTAGE (V)
Supply Bias Current
vs. LED Anode Voltage
8
VIN = 5.5V
7
6
5
4
VIN = 3.5V
3 ^{VIN = 2.5V}
2
1
0
5.5
RSET = 4.64kΩ
5 4.5 4 3.5 3 2.5
LED BATTERY VOLTAGE (V)
LED Current
vs. PWM Duty Cycle
900
800
f_PWM = 20kHz
700
600
f_PWM = 100kHz
500
400 ^fPWM ^{= 200kHz}
300
200
100
0
0
f_PWM = 500kHz
20
40
60
80 100
DUTY CYCLE (%)
LED Current
vs. LED Anode Voltage
1
0.9
VIN = 5.5V
0.8
VIN = 3.5V
0.7
0.6
VIN = 3.0V
0.5
0.4
0.3
0.2
0.1
0
5.5 5 4.5 4 3.5 3 2.5
LED ANODE VOLTAGE (V)
10000
Peak LED Current
vs. R_SET
1000
100
10
1
1
10
100 1000 10000
RSET (kΩ)
RSET Voltage
vs. LED Current
1.4
1.38
1.36
1.34
1.32
1.3
1.28
1.26
1.24
0
VIN = 5V
200 400 600 800 1000 1200 1400
LED CURRENT (mA)
MIC4802
500
450
400
350
300
250
200
150
100
50
0
0
Dropout Voltage
vs. LED Current
VIN = 5V
200 400 600 800 1000 1200 1400
LED CURRENT (mA)
LED Current
vs. PWM Duty Cycle
900
VIN = 5V
800
700
f_PWM = 1kHz
600
500
f_PWM = 5kHz
400
300
200
fPWM = 10kHz
100
0
0
20
40
60
80 100
DUTY CYCLE (%)
Typical I_LED vs. V_LED
2
1.8 ^{VIN = 5.0V}
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
2.4 2.6 2.8 3 3.2 3.4 3.6
LED FORWARD VOLTAGE (V)
January 2011
4
M9999-013111-B