CM4072 Datasheet, PDF (5/11 Pages) California Micro Devices Corp – Low Noise Charge Pump/Linear Regulator LED Driver

PRELIMINARY
CM4072
Performance Information
p
1.00E-03
1.00E-04
1.00E-05
1.00E-06
noise floor
Cs=1.5uF
1.00E-07
1.00E-08
10
100
1000
10000
Frequency [Hz]
100000
Note: Noise peaks may appear for different values of C_P, C_S & I_OUT, and are due to the ripple frequency of the charge pump (see later).
Figure 1. CM4072 Noise Spectrum ( T_A = 25°C, C_P=0.47μF, C_S = 1.5μF,
C_OUT = 10μF, C_BYP = 0.1μF, I_OUT =100mA )
70.0
60.0
50.0
40.0
30.0
20.0
10.0
0.0
10
100
1000
10000
100000
Frequency [Hz]
Measured by forcing V_IN voltage to 3.3V & 5.0V dc, then sweeping 100mV ac on V_IN. C_OUT = 10μF, C_BYP = 0.1μF.
Figure 2. CM4072 PSRR (upper curve with V_IN = 3.3V, lower curve
with V_IN = 5V, I_OUT = 100mA both cases)
© 2005 California Micro Devices Corp. All rights reserved.
11/08/05
490 N. McCarthy Blvd., Milpitas, CA 95035-5112 ● Tel: [phone] ● Fax: [phone] ● www.cmd.com 5