LTC3810-5 Datasheet, PDF (33/36 Pages) Linear Technology – 60V Current Mode Synchronous Switching Regulator Controller

LTC3810-5
APPLICATIONS INFORMATION
• Use compact plane for switch node (SW) to improve
cooling of the MOSFETs and to keep EMI down.
• Use planes for V_IN and V_OUT to maintain good voltage
filtering and to keep power losses low.
• Flood all unused areas on all layers with copper. Flooding
with copper will reduce the temperature rise of power
component. You can connect the copper areas to any
DC net (V_IN, V_OUT, GND or to any other DC rail in your
system).
When laying out a printed circuit board, without a ground
plane, use the following checklist to ensure proper opera-
tion of the controller.
• Segregate the signal and power grounds. All small
signal components should return to the SGND pin at
one point which is then tied to the PGND pin close to
the source of M2.
• Place M2 as close to the controller as possible, keeping
the PGND, BG and SW traces short.
• Connect the input capacitor(s) C_IN close to the pow-
er MOSFETs. This capacitor carries the MOSFET AC
current.
• Keep the high dV/dt SW, BOOST and TG nodes away
from sensitive small-signal nodes.
• Connect the INTV_CC decoupling capacitor C_VCC closely
to the INTV_CC and SGND pins.
• Connect the top driver boost capacitor C_B closely to
the BOOST and SW pins.
• Connect the bottom driver decoupling capacitor C_DRVCC
closely to the DRV_CC and BGRTN pins.
TYPICAL APPLICATIONS
PGOOD
SHDN
R_UV1
470k
R_UV2
61.9k
7V to 60V Input Voltage to 5V/5A with IC Power from 12V Supply
and All Ceramic Output Capacitors
R_ON
110k
C_ON
100pF
C_SS
1000pF
LTC3810-5
31 _ION
BOOST ²⁷
2
3
V_ON
V_RNG
4 _PGOOD
5 _{MODE_SYNC}
6 _ITH
7
8
V_FB
PLL/LPF
TG ²⁶
SW ²⁵
SENSE^{+ 24}
SENSE^{– 20}
BGRTN ¹⁹
9
SS/TRACK
33
12
SGND
SHDN
13 _UVIN
18
BG
17
DRV_CC
16
INTV_CC
EXTV_CC
15
14
NDRV
C_C2
47pF
C_C1
R_FB2
R_C
100k
5pF
1.91k
SGND
R_FB1
10k
12V
DB
BAS19
C_B 0.1μF
C_DRVCC
0.1μF
C_VCC
1μF
C5
22μF
C_IN1
68μF
100V
M1
Si7850DP
V_IN
7V TO 60V
C_IN2
1μF
100V
PGND
L1
4.7μH
M2
Si7850DP
D1
B1100
PGND
V_OUT
5V
5A
C_OUT
47μF
6.3V
s3
38105 TA03
38105fc
33