MIC2178 Datasheet, PDF (12/16 Pages) Micrel Semiconductor – 2.5A Synchronous Buck Regulator

MIC2178
The feedback resistors, RC compensation network, and
BIAS pin bypass capacitor should be located close to their
respective pins. To prevent ground bounce, their ground
traces and SGND should not be in the path of switching
Micrel
currents returning to the power supply ground bus. SGND
and PGND should be tied together by a ground plane that
extends under the MIC2178.
V_IN
4.5V to 16.5V
C1
22µF
35V
R1
20k
Skip Mode
PWM Mode
U1
1,2,9
20 _EN
VIN
3,8
SW
11 _PWRGD
4–7
10
MIC2178
PWM
PGND
18 _SYNC
FB ¹²
COMP SGND BIAS
13
R2
10k
C4
6.8nF
14–17
19
C3
0.01µF
L1
50µH
D1
MBRS130L
V_OUT
3.3V/1A
C2
100µF
10V
U1 Micrel MIC2178-3.3BWM
C1 AVX
TPSE226M035R0300, ESR = 0.3Ω
C2 AVX
TPSD107M010R0100, ESR = 0.1Ω
C3 Z5UorX7R Ceramic Dielectric Material
C4 X7RorNP0 Ceramic Dielectric Material
D1 Motorola MBRS130LT3
L1 Coiltronics CTX50-4P, DCR = 0.097Ω
L1 Coilcraft DO3316P-473, DCR = 0.12Ω
L1 Bi
HM77-11003, DCR = 0.073Ω
Figure 1. MIC2178 4.5V–16.5V to 3.3V/1A Regulator
V_IN
5.4V to 16.5V
C1
22µF
35V
R1
20k
Skip Mode
PWM Mode
U1
1,2,9
20 _EN
VIN
3,8
SW
11 _PWRGD
4–7
MIC2178 PGND
10 _PWM
L1
50µH
D1
MBRS130L
V_OUT
5V/1A
C2
100µF
10V
18 _SYNC
COMP
13
R2
10k
C4
6.8nF
SGND
14–17
FB ¹²
U1
BIAS
C1
19
C2
C3
C3
0.01µF
C4
D1
L1
L1
L1
Micrel MIC2178-5.0BWM
AVX
TPSE226M035R0300, ESR = 0.3Ω
AVX
TPSD107M010R0100, ESR = 0.1Ω
Z5UorX7R Ceramic Dielectric Material
X7RorNP0 Ceramic Dielectric Material
Motorola MBRS130LT3
Coiltronics CTX50-4P, DCR = 0.097Ω
Coilcraft DO3316P-473, DCR = 0.12Ω
Bi
HM77-11003, DCR = 0.073Ω
Figure 2. MIC2178 5.4V–16.5V to 5V/1A Regulator
MIC2178
12
June 1998