LTM4641
TYPICAL APPLICATIONS
MSP
4.5V < V < 15V
IN
+
C
C
IN(MLCC)
IN(BULK)
22µF
25V
×2
100µF
25V
V
V
V
SW
V
ING INGP INH
OUT
V
V
1.2V NOMINAL
INL
OUT
R
UP TO 10A OUTPUT
fSET
1.13M
MCB
CROWBAR
100µF
6.3V
×4
f
SET
LATCHOFF
UVLO
HYST
FCB
LATCH
RESET
ADDITIONAL
FAULT INDICATOR
R
SET1A
8.2k
+
V
ORB
+
V
LOCAL HIGH
FREQUENCY
DECOUPLING
OSNS
LTM4641*
R
SET1B
8.2k
LOAD
INTV
DRV
CC
–
V
OSNS
CC
–
V
IOVRETRY
OVLO
ORB
TEMP
R30
35.7k
MSP: NXP PSMN017-30LL
MCB: NXP PSMN5R0-30YL
1V
REF
OVPGM
OTBH
PGOOD
V
PWR
V
IN_SNS
†
3.3V
RUN
V
DD33
V
OUT_EN0
TRACK/SS
TMR COMP SGND GND
TO UPSTREAM
V
IN_EN
SYSTEM ENABLE
C
SS
4.7nF
SDA
LTC2978**
PMBus
INTERFACE
SCL
ALERT
V
DACPO
CONTROL0
V
SENSEPO
V
SENSEMO
WP
WRITE PROTECT
V
DACMO
*LTM4641 SGND CONNECTS TO GND INTERNAL TO MODULE.
KEEP SGND ROUTES/PLANES SEPARATE FROM GND ON MOTHERBOARD
TO/FROM
OTHER
LTC2978s
FAULTOO
SHARE_CLK
PWRGD
WDI/RESET
ASELO ASEL1
TO µP RESET INPUT
**ONLY ONE OF EIGHT LTC2978 CHANNELS SHOWN. LTC2978 PULL-UPS,
BYPASSING COMPONENTS, AND SOME PINS NOT SHOWN. FOR DETAILS
OF LTC2978 IMPLEMENTATION, SEE LTC2978 DATA SHEET
WATCHDOG TIMER INTERRUPT
GND
†
LTC2978 MAY BE POWERED FROM EITHER AN EXTERNAL 3.3V
SUPPLY OR THE SYSTEM BUS
Figure 60. Fault-Protected Load with Power Supply Management. LTM4641’s Fast Output Overvoltage Latchoff Trip
Threshold Remains Consistently 11% Above LTC2978-Commanded Target VOUT, Even as VOUT is Margined Via I2C
V
V
OUT
200mV/DIV
OUT
200mV/DIV
V
V
DACPO
500mV/DIV
DACPO
500mV/DIV
SDA, SCL
2V/DIV
SDA, SCL
2V/DIV
4641 F61a
4641 F61b
20ms/DIV
20ms/DIV
(61a) PMBus OPERATION (Reg. 0x01): 0x80 → 0xA8 (Margin High)
(61b) PMBus OPERATION (Reg. 0x01): 0xA8 → 0x80 (Margin Off)
V
V
OUT
OUT
200mV/DIV
200mV/DIV
V
V
DACPO
DACPO
500mV/DIV
500mV/DIV
SDA, SCL
2V/DIV
SDA, SCL
2V/DIV
4641 F61d
4641 F61c
20ms/DIV
20ms/DIV
(61c) PMBus OPERATION (Reg. 0x01): 0x80 → 0x98 (Margin Low)
(61d) PMBus OPERATION (Reg. 0x01): 0x98 → 0x80 (Margin Off)
Figure 61. LTM4641’s VOUT Margined High/Low by LTC2978 Via I2C Commands. Figure 60 Circuit. 12VIN.
VOUT_COMMAND (0x21) = 1.20V, VOUT_MARGIN_HIGH (0x25) = 1.32V, VOUT_MARGIN_LOW (0x26) = 1.08V
4641f
54