Datasheet

 2013 Microchip Technology Inc. DS22331A-page 41
MCP19111
6.6 Compensation Setting
The MCP19111 uses a peak current mode control
architecture. A control reference is used to regulate the
peak current of the converter directly. The inner current
loop essentially turns the inductor into a voltage-
controlled current source. This reduces the control-to-
output transfer function to a simple single-pole model of
a current source feeding a capacitor. The desired
response of the overall loop can be tuned by proper
placement of the compensation zero frequency and
gain. Figure 6-1 shows a simplified drawing of the
internal compensation. See Register 6-6 for the
adjustable zero frequency and gain settings.
FIGURE 6-1: SIMPLIFIED
COMPENSATION
V
REF
+V
SEN
-V
SEN
REGISTER 6-6: CMPZCON: COMPENSATION SETTING CONTROL REGISTER
R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x R/W-x
CMPZF3 CMPZF2 CMPZF1 CMPZF0 CMPZG3 CMPZG2 CMPZG1 CMPZG0
bit 7 bit 0
Legend:
R = Readable bit W = Writable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 7-4 CMPZF<3:0>: Compensation Zero Frequency Setting bits
0000 = 1500 Hz
0001 = 1850 Hz
0010 = 2300 Hz
0011 = 2840 Hz
0100 = 3460 Hz
0101 = 4300 Hz
0110 = 5300 Hz
0111 = 6630 Hz
1000 = 8380 Hz
1001 = 9950 Hz
1010 = 12200 Hz
1011 = 14400 Hz
1100 = 18700 Hz
1101 = 23000 Hz
1110 = 28400 Hz
1111 = 35300 Hz
bit 3-0 CMPZG<3:0>: Compensation Gain Setting bits
0000 = 36.15 dB
0001 = 33.75 dB
0010 = 30.68 dB
0011 = 28.43 dB
0100 = 26.10 dB
0101 = 23.81 dB
0110 = 21.44 dB
0111 = 19.10 dB
1000 = 16.78 dB
1001 = 14.32 dB
1010 = 12.04 dB
1011 = 9.54 dB
1100 = 7.23 dB
1101 = 4.61 dB
1110 = 2.28 dB
1111 = 0.00 dB