MAX16051 Maxim Integrated Products, MAX16051 Datasheet - Page 17

• Manufacturer Part Number: MAX16051
• Description: Voltage Monitors/Sequencer Circuits
• Manufacturer: Maxim Integrated Products

The MAX16050/MAX16051 can be daisy-chained to
sequence and monitor a large number of voltages
(Figure 7). When a fault occurs on any of the monitored
inputs, FAULT goes low, signaling a fast power-down.
Connect all FAULT pins of the MAX16050/MAX16051
together to ensure that all power supplies are turned off
during a fault.
In Figure 7, SHDN is pulled low to initiate the power-
down sequence. When all of the supply voltages moni-
tored by U2 are off, the bus removal output (REM) goes
high, thereby allowing U1 to start sequencing down.
REM normally is at a logic-low state when all voltages
are good. Connect U2’s REM to U1’s EN_HOLD to
force U1 to stay on even if EN and SHDN are pulled
low. This enable-and-hold circuitry allows the system to
power down correctly.
Table 2. Recommended MOSFETs
MANUFACTURER
Daisy-Chaining the MAX16050/MAX16051
International
Fairchild
Rectifier
Vishay
Voltage Monitors/Sequencer Circuits with
______________________________________________________________________________________
SUD50N02-09P
IRLML2502
FDB8030L
FDD6672A
FDP8030L
Si1488DH
FDC633N
Si7136DP
Si4872DY
IRL3715Z
FDS8876
IRL3716
IRL3402
PART
V
(V)
30
30
30
30
20
30
20
20
20
20
20
20
DS
Reverse-Sequencing Capability
V
(max)
0.67
0.95
GSth
(V)
1.5
1.2
2.5
0.7
2.1
1.2
3
1
3
3
R
DSON
AT V
(mΩ)
15.5
4.5
9.5
4.5
4.8
42
17
10
17
49
10
45
The external pass MOSFET connects in series with the
sequenced power-supply source. Since the load cur-
rent and the MOSFET drain-to-source impedance
(R
istics of the MOSFET affect the load supply accuracy.
For highest supply accuracy and lowest voltage drop,
select a MOSFET with an appropriate drain-to-source
on-resistance with a gate-to-source bias of 4.5V to 6.0V
(see Table 2).
For better noise immunity, bypass V
0.1µF capacitor installed as close to the device as pos-
sible. Bypass ABP to GND with a 1µF capacitor
installed as close to the device as possible; ABP is an
internally generated voltage and must not be used to
supply more than 1mA to external circuitry. Connect the
exposed pad (EP) to the ground plane for improved
heat dissipation. Do not use EP as the only ground con-
nection for the device.
GS
DSON
= 4.5V
) determine the voltage drop, the on-character-
VOLTAGE DROP (A)
I
MAX
11.11
11.11
1.19
5.26
2.94
2.94
1.02
10.4
3.22
1.11
AT 50mV
5
5
Layout and Bypassing
MOSFET Selection
78 (max)
Qg (nC)
www.DataSheet4U.com
(TYP)
24.5
10.5
120
11
33
15
27
53
6
7
8
CC
to GND with a
FOOTPRINT
TO-263AB
TO-220AB
TO220AB
TO220AB
SOT-363
SOT23-3
Micro3
SOT
TO-220
TO-252
TO-252
SC70-6
TO-262
TO-262
D
D
Super
SO-8
SO-8
SO-8
2
2
PAK
PAK
TM
-6
TM
17