SC600AIMLTRT Semtech, SC600AIMLTRT Datasheet - Page 9

• Manufacturer Part Number: SC600AIMLTRT
• Description: IC, LED DRIVER, CHARGE PUMP, MLPD-10
• Manufacturer: Semtech

Specifications of SC600AIMLTRT

• Led Driver Application: LED Backlighting, Portable Electronics
• No. Of Outputs: 1
• Output Current: 60mA
• Output Voltage: 5.25V
• Input Voltage: 2.5V To 6.5V
• Topology: Charge Pump
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Brightness Control with PWM Input
Brightness control using a PWM input can be achieved
with the application circuit below. Note that by connecting
CX8 to the PWM signal the switching frequency is changed
as the PWM signal changes. The charge pump operates
at 262kHz during the on-time when there is a demand for
POWER MANAGEMENT
Applications Information (Cont.)
© 2006 Semtech Corp.
500
450
400
350
300
250
200
150
100
50
0
2.8
3.3
Ripple Voltage vs. Input Voltage
3.8
2 .7V to 6. 5V
Input Voltage [V]
PW M
C in
1 uF
4.3
White LED Driver Circuit with PWM Brightness Control
4.8
Voltage Waveforms for LED Driver Circuit
3
4
6
5
VI N
C D4
C X8
EN
5.3
GN D
U1
8
C F1 +
C F1 -
C F2 -
VOUT
C F2 +
5.8
Vout p-p
Vin p-p
1 0
9
7
1
2
9
C buck et1
1 uF
C buck et2
1 uF
current, and then changes to 32kHz when there is no load
current. This is done to save battery power by taking ad-
vantage of the lower 280μA quiescent current at 32kHz.
The ripple voltage seen at the output is reasonable for
LED applications, but the output capacitance can be in-
creased to reduce the ripple if required. The sum of the
LED currents for this circuit is 55mA during the on-time.
120
100
80
60
40
20
0
2. 8
5.0 V
Cout
1uF
3
10 0
Battery Current vs. Input Voltage
10 0
3. 2
for Various Duty Cycles
Input Voltage [V]
10 0
3. 4
3. 6
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SC600
3. 8
89.20%
70.30%
50.20%
30.20%
4