MIC23153 Datasheet, PDF (13/18 Pages) Micrel Semiconductor – 4MHz PWM 2A Buck Regulator with HyperLight Load™ and Power Good

Micrel Inc.
PWM mode is a function of the input voltage (V_IN), output
voltage (V_OUT), duty cycle (D), inductance (L) and
frequency (f). As shown in Figure 3, as the Output
Current increases, the switching frequency also
increases until the MIC23153 goes from HyperLight
Load™ mode to PWM mode at approximately 120mA.
The MIC23153 will switch at a relatively constant
frequency around 4MHz once the output current is over
120mA.
MIC23153
10000
1000
Switching Frequency
vs. Load Current
L = 2.2µH
100
L = 1µH
10
1
VOUT = 1.8V
0.1
0.0001 0.001 0.01 0.1
1
10
LOAD CURRENT (A)
Figure 3. SW Frequency vs. Output Current
December 2009
13
M9999-121409-A