MAX5925AEUB [MAXIM]
1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor; 1V至13.2V , n沟道热插拔控制器,无需检测电阻型号: | MAX5925AEUB |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | 1V to 13.2V, n-Channel Hot-Swap Controllers Require No Sense Resistor |
文件: | 总20页 (文件大小:985K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-3443; Rev 0; 10/04
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
General Description
Features
♦ Hot Swap 1V to 13.2V with V
♦ Drive High-Side n-Channel MOSFET
♦ Operation With or Without R
≥ 2.25V
The MAX5924/MAX5925/MAX5926 1V to 13.2V hot-swap
controllers allow the safe insertion and removal of circuit
cards into live backplanes. These devices hot swap sup-
plies ranging from 1V to 13.2V provided that the device
CC
SENSE
♦ Protected During Turn-On into Shorted Load
♦ Circuit-Breaker Threshold Adjustable Down to
supply voltage, V , is at or above 2.25V and the hot-
CC
S
swapped supply, V , does not exceed V
.
CC
10mV
The MAX5924/MAX5925/MAX5926 hot-swap controllers
limit the inrush current to the load and provide a circuit-
breaker function for overcurrent protection. The devices
operate with or without a sense resistor. When operat-
ing without a sense resistor, load-probing circuitry
ensures a short circuit is not present during startup,
then gradually turns on the external MOSFET. After the
load probing is complete, on-chip comparators provide
overcurrent protection by monitoring the voltage drop
across the external MOSFET on-resistance. In the event
of a fault condition, the load is disconnected.
♦ Programmable Slew-Rate Control
♦ Circuit Breaker with Temperature-Compensated
RDS(ON) Sensing
♦ Programmable Turn-On Voltage
♦ Autoretry or Latched Fault Management
♦ 10-Pin µMAX or 16-Pin QSOP Packages
Ordering Information
PART
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
10 µMAX
The MAX5924/MAX5925/MAX5926 include many inte-
grated features that reduce component count and
design time, including programmable turn-on voltage,
slew rate, and circuit-breaker threshold. An on-board
charge pump provides the gate drive for a low-cost,
external n-channel MOSFET.
MAX5924AEUB
MAX5924BEUB*
MAX5924CEUB*
MAX5924DEUB*
MAX5925AEUB
MAX5925BEUB*
MAX5925CEUB*
MAX5925DEUB*
MAX5926EEE*
10 µMAX
10 µMAX
10 µMAX
10 µMAX
The MAX5924/MAX5925/MAX5926 are available with
open-drain PGOOD and/or PGOOD outputs. The
devices also feature a circuit breaker with temperature-
10 µMAX
10 µMAX
compensated R
sensing. The MAX5926 features
10 µMAX
DS(ON)
a selectable 0ppm/°C or 3300ppm/°C temperature coef-
ficient. The MAX5924 temperature coefficient is
0ppm/°C and the MAX5925 temperature coefficient is
3300ppm/°C. Autoretry and latched fault-management
configurations are available (see the Selector Guide).
16 QSOP–EP**
*Future product—contact factory for availability.
**EP = Exposed pad.
Typical Operating Circuits
Applications
TYPICAL OPERATION WITHOUT R
SENSE
Base Stations
BACKPLANE
REMOVABLE CARD
N
RAID
V
1V TO V
OUT
CC
V
S
2.25V TO 13.2V
Remote-Access Servers
Network Routers and Switches
Servers
V
CC
R
CB
R
SC
OUT
CB
GATE SENSE
Portable Device Bays
SC_DET
V
CC
MAX5925
MAX5926
GND
GND
µMAX is a registered trademark of Maxim Integrated Products, Inc.
SEE FIGURE 1 FOR A DETAILED TYPICAL OPERATING CIRCUIT WITHOUT R
.
SENSE
Selector Guide appears at end of data sheet.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND, unless otherwise noted).
Continuous Power Dissipation (T = +70°C)
A
V
CC
.........................................................................-0.3V to +14V
10-Pin µMAX (derate 6.9mW/°C above +70°C)...........556mW
16-Pin QSOP (derate 18.9mW/°C above +70°C).......1509mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature .....................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
GATE*.....................................................................-0.3V to +20V
All Other Pins .........-0.3V to the lower of (V + 0.3V) and +14V
CC
SC_DET Current (200ms pulse width, 15% duty cycle) ...140mA
Continuous Current (all other pins).....................................20mA
*GATE is internally driven and clamped. Do not drive GATE with external source.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V , EN (MAX5924/MAX5925), EN1 (MAX5926) = +2.25V to +13.2V; EN2 (MAX5926) = 0V; V (see Figure 1) = +1.05V to V ; T =
CC
S
CC
A
-40°C to +85°C, unless otherwise noted. Typical values are at V
= 5V, R = 500Ω from OUT to GND, C = 100µF, SLEW = open,
CC
L
L
T
= +25°C, unless otherwise noted.) (Note 1)
A
PARAMETER
POWER SUPPLIES
Operating Range
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
V
2.25
1.05
13.20
V
V
CC
CC
V Operating Range
S
V
V as defined in Figure 1
V
CC
S
S
Supply Current
I
FET on, SC_DET = V
1.5
2.5
2.25
350
mA
CC
CC
UNDERVOLTAGE LOCKOUT (UVLO)
UVLO Threshold
V
Default value, V and V increasing, Figure 1
1.86
123
2.06
900
277
V
UVLO
S
CC
V
V
UVLO Deglitch Time
UVLO Startup Delay
t
(Note 2)
µs
ms
CC
CC
DG
t
D,UVLO
LOAD-PROBE
2.25V < V
< 5V
4
3
30
10
65
20
CC
Load-Probe Resistance (Note 3)
R
LP
Ω
5V < V
< 13.2V
CC
Load-Probe Timeout
t
61
180
102
200
163
220
ms
mV
LP
Load-Probe Threshold Voltage
CIRCUIT BREAKER
V
(Note 4)
LP,TH
I
TC = high (MAX5926), MAX5924
= 2.25V,
35
44
37
51
42
58
CB
V
CC
T
= +25°C
A
TC = low (MAX5926),
MAX5925 (Note 5)
I
I
CB25
CB85
5V ≤ V
≤ 13.2V,
CC
49
47
58
54
52
63
58
60
70
Circuit-Breaker Programming
Current
T
= +25°C
A
µA
V
= 2.25V,
CC
T
= +85°C
A
TC = low (MAX5926),
MAX5925 (Note 5)
5V ≤ V
≤ 13.2V,
CC
T
= +85°C
A
Circuit-Breaker Programming
Current During Startup
I
2 x I
µA
V
CB,SU
CB
(No R
)
SENSE
Circuit-Breaker Enable Threshold
(No R
V
V
- V , rising gate voltage (Note 6)
OUT
4.0
CB,EN
GATE
)
SENSE
2
_______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
ELECTRICAL CHARACTERISTICS (continued)
(V , EN (MAX5924/MAX5925), EN1 (MAX5926) = +2.25V to +13.2V; EN2 (MAX5926) = 0V; V (see Figure 1) = +1.05V to V ; T =
CC
S
CC
A
-40°C to +85°C, unless otherwise noted. Typical values are at V
= 5V, R = 500Ω from OUT to GND, C = 100µF, SLEW = open,
CC
L
L
T
= +25°C, unless otherwise noted.) (Note 1)
A
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Circuit-Breaker Comparator
Offset Voltage
V
0.3
4.7
mV
CB_OS
Fast Circuit-Breaker Offset
Resistor
R
Figure 3
1.2
1.9
2.5
kΩ
CBF
Slow Circuit-Breaker Delay
Fast Circuit-Breaker Delay
t
V
V
- V
- V
= 10mV
0.95
1.6
2.80
ms
ns
CBS
CB
CB
SENSE
t
= 500mV
280
CBF
SENSE
Circuit-Breaker Trip Gate
Pulldown Current
I
V
= 2.5V, V
= 13.2V
20
27
mA
GATE,PD
GATE
CC
MAX5924, TC = high (MAX5926)
MAX5925, TC = low (MAX5926)
0
Circuit-Breaker Temperature
Coefficient
TC
ppm/°C
ICB
3300
MOSFET DRIVER
2.25V ≤ V
≤ 12.6V
3.46
3.33
2.19
0.44
239
4.91
5
6.70
6.70
CC
External Gate Drive
V
V
- V
V
GS
GATE
OUT
V
= 13.2V (Note 7)
CC
SLEW = open, C
= 10nF
9.5
0.84
16.00
1.18
GATE
Load Voltage Slew Rate
SR
V/ms
µA
SLEW = 300nF, C
= 10nF (Note 8)
GATE
Gate Pullup Current Capacity
I
V
= 0V
GATE
GATE
ENABLE COMPARATOR
V
V
(MAX5924/MAX5925) or
EN
EN, EN1 Reference Threshold
EN, EN1 Hysteresis
V
0.755
0.795
30
0.836
50
V
EN/UVLO
(MAX5926) rising
EN1
V
mV
nA
EN,HYS
EN (MAX5924/MAX5925) = V
EN1 (MAX5926) = V
,
CC
EN, EN1 Input Bias Current
I
8
EN
CC
DIGITAL OUTPUTS (PGOOD, PGOOD)
Power-Good Output Low Voltage
V
I
= 1mA
OL
0.3
0.2
0.4
1
V
OL
Power-Good Output Open-Drain
Leakage Current
I
PGOOD/PGOOD = 13.2V
- V , rising gate voltage
µA
OH
Power-Good Trip Point (% of V ) V
GS
V
50
70
99
%
V
THPGOOD
GATE
OUT
Power-Good Hysteresis
V
0.36
PG,HYS
LOGIC AND TIMING (TC, LATCH (MAX5926), EN2 (MAX5926)
Autoretry Delay
t
Autoretry mode
1.0
2.0
1.6
3
2.6
0.4
s
V
RETRY
V
IH
Input Voltage
V
IL
Input Bias Current
I
Logic high at 13.2V
µA
BIAS
_______________________________________________________________________________________
3
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
ELECTRICAL CHARACTERISTICS (continued)
(V , EN (MAX5924/MAX5925), EN1 (MAX5926) = +2.25V to +13.2V; EN2 (MAX5926) = 0V; V (see Figure 1) = +1.05V to V ; T =
CC
S
CC
A
-40°C to +85°C, unless otherwise noted. Typical values are at V
= 5V, R = 500Ω from OUT to GND, C = 100µF, SLEW = open,
CC
L L
T
= +25°C, unless otherwise noted.) (Note 1)
A
Note 1: All devices are 100% tested at T = +25°C and +85°C. All temperature limits at -40°C are guaranteed by design.
A
Note 2: V
drops 30% below the undervoltage lockout voltage during t
are ignored.
CC
DG
Note 3: R is the resistance measured between V
and SC_DET during the load-probing phase, t .
LP
CC
LP
Note 4: Guaranteed by design.
Note 5: The circuit-breaker programming current increases linearly from V
Supply Voltage graph in the Typical Operating Characteristics.
Note 6: See the Startup Mode section for more information.
= 2.25V to 5V. See the Circuit-Breaker Current vs.
CC
Note 7: V
is clamped to 17V (typ) above ground.
GATE
-9
Note 8: dv/dt = 330 x 10 /C
(V/ms), nMOS device used for measurement was IRF9530N. Slew rate is measured at the load.
SLEW
Typical Operating Characteristics
(V
= 5V, C = 100µF, C
= 330nF, C
= 10nF, R = 500Ω, Figure 1, T = +25°C, unless otherwise noted.)
CC
L
SLEW
GATE L A
MAX5926 SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5926 SUPPLY CURRENT
vs. TEMPERATURE
GATE-DRIVE VOLTAGE
vs. SUPPLY VOLTAGE
2.0
2.4
2.0
1.6
1.2
0.8
0.4
0
7
6
5
4
3
2
V
= V
S
V
= V
CC
CC
S
ENABLED
V
= 13.2V
CC
1.6
1.2
0.8
0.4
0
V
CC
= 5.0V
V
= 1V
DISABLED
S
V
= V
CC
S
V
= 3V
S
V
= 5V
S
V
= 3.0V
CC
V
= 2.25V
10
CC
2
4
6
8
10
12
14
-40
-15
35
60
85
2
4
6
8
10
12
14
V
(V)
TEMPERATURE (°C)
V
(V)
CC
CC
CIRCUIT-BREAKER CURRENT
vs. HOT-SWAP VOLTAGE
CIRCUIT-BREAKER CURRENT
vs. SUPPLY VOLTAGE (TC = 3300ppm/°C)
GATE-DRIVE VOLTAGE
vs. TEMPERATURE
6.0
5.5
5.0
4.5
4.0
3.5
3.0
56
52
48
44
40
36
55
53
51
49
47
V
= V
V
= V
CC S
CC
S
V
= 5.0V
CC
TC = 3300ppm/°C
V
= 3.0V
CC
V
= 13.2V
CC
TC = 0ppm/°C
V
= 13.2V
12
CC
-40
-15
10
35
60
85
0
2
4
6
8
10
14
2
4
6
8
10
12
14
TEMPERATURE (°C)
V
(V)
V
(V)
CC
S
4
_______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Typical Operating Characteristics (continued)
(V
= 5V, C = 100µF, C
= 330nF, C
= 10nF, R = 500Ω, Figure 1, T = +25°C, unless otherwise noted.)
CC
L
SLEW
GATE
L
A
CIRCUIT-BREAKER PROGRAMMING
CURRENT vs. TEMPERATURE
CIRCUIT-BREAKER CURRENT
vs. SUPPLY VOLTAGE (TC = 0ppm/°C)
80
39.4
39.2
39.0
38.8
38.6
38.4
38.2
V
= V = 5V
S
V
= V
S
CC
CC
70
60
50
40
30
20
TC = 3300ppm/°C
TC = 0ppm/°C
-40
-15
10
35
60
85
2
4
6
8
10
12
14
TEMPERATURE (°C)
V
(V)
CC
TURN-ON WAVEFORM
(C = OPEN)
TURN-ON WAVEFORM
(C = 330nF)
SLEW
SLEW
MAX5924 toc09
MAX5924 toc10
GATE
5V/div
0V
GATE
5V/div
0V
OUT
5V/div
0V
OUT
5V/div
0V
PGOOD
5V/div
0V
PGOOD
5V/div
0V
200µs/div
2ms/div
TURN-OFF WAVEFORM
OVERCURRENT CIRCUIT-BREAKER EVENT
MAX5924 toc11
MAX5924 toc12
1A/div
0A
EN1
5V/div
0V
I
FET
t
CBS
GATE
5V/div
0V
10V/div
GATE
OUT
0V
10V/div
0V
PGOOD
5V/div
0V
5V/div
0V
PGOOD
2µs/div
400µs/div
_______________________________________________________________________________________
5
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Typical Operating Characteristics (continued)
(V
= 5V, C = 100µF, C
= 330nF, C
= 10nF, R = 500Ω, Figure 1, T = +25°C, unless otherwise noted.)
CC
L
SLEW
GATE
L
A
AUTORETRY DELAY
SHORT-CIRCUIT CIRCUIT-BREAKER EVENT
MAX5924 toc14
MAX5924 toc13
I
FET
1A/div
EN1
5V/div
0V
t
D,UVLO
0A
t
RETRY
GATE
OUT
5V/div
5V/div
0V
SC_DET
OUT
0V
5V/div
0V
100mV/div
0V
5V/div
0V
PGOOD
2µs/div
400ms/div
OVERCURRENT FAULT AND
UVLO DELAY AND LOAD PROBING
AUTORETRY DELAY
MAX5924 toc16
MAX5924 toc15
EN1
EN1
5V/div
0V
5V/div
0V
GATE
5V/div
0V
t
t
LP
D,UVLO
5V/div
0V
5V/div
0V
SC_DET
OUT
SC_DET
OUT
100mV/div
0V
200mV/div
0V
40ms/div
400ms/div
UVLO RESPONSE
UVLO DEGLITCH RESPONSE
MAX5924 toc17
MAX5924 toc18
>t
DG
2V/div
GATE
GATE
2V/div
0V
<t
DG
0V
1V/div
1V/div
0V
V
CC
V
CC
0V
200µs/div
200µs/div
6
_______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Pin Description
PIN
MAX5924A/ MAX5924B/
MAX5924C/ MAX5924D/
MAX5925A/ MAX5925B/
MAX5925C MAX5925D
NAME
FUNCTION
MAX5926
Power-Supply Input. Connect V
to a voltage between 2.25V and 13.2V.
CC
1
1
1
V
CC
V
must always be equal to or greater than V (see Figure 1).
S
CC
Short-Circuit Detection Output. SC_DET forces current into the external load
through a series resistor, R , at startup to determine whether there is a short
SC
circuit (load probing). Select R based on the desired slow-comparator trip
SC
current (see the Selecting a Circuit-Breaker Threshold section). Connect
2
2
2
SC_DET
EN
SC_DET to V when using R , or to disable load probing when it is not
CC SENSE
desired.
ON/OFF Control Input. Drive EN high to enable the device. Drive EN low to
disable the device. An optional external resistive-divider connected between
3
3
—
V
, EN, and GND sets the programmable turn-on voltage.
CC
4
—
5
—
4
4
7
5
PGOOD Open-Drain Active-Low Power-Good Output
PGOOD Open-Drain Active-High Power-Good Output
5
GND
Ground
Slew-Rate Adjustment Input. Connect an external capacitor between SLEW and
GND to adjust the gate slew rate. Leave SLEW unconnected for the default
slew rate.
6
6
12
SLEW
Gate-Drive Output. Connect GATE to the gate of the external n-channel
MOSFET.
7
8
7
8
13
14
GATE
OUT
Output Voltage. Connect OUT to the source of the external MOSFET.
Circuit-Breaker Sense Input. Connect SENSE to OUT when not using an
9
9
15
16
SENSE external R
(Figure 1). Connect SENSE to the drain of the external
SENSE
MOSFET when using an external R
(Figure 2).
SENSE
Circuit-Breaker Threshold Input. Connect an external resistor, R , from CB to
V to set the circuit-breaker threshold voltage.
S
CB
10
10
CB
Active-High ON/OFF Control Input. Drive EN1 high to enable the device when
EN2 is low. Drive EN1 low to disable the device, regardless of the state of EN2.
An optional external resistive-divider between V , EN1, and GND sets the
CC
—
—
3
EN1
programmable turn-on voltage while EN2 is low.
Active-Low ON/OFF Control Input. Drive EN2 low to enable the device when
EN1 is high. Drive EN2 high to disable the device, regardless of the state of
EN1.
—
—
—
—
—
—
6
8
9
EN2
LATCH
TC
Latch Mode Input. Drive LATCH low for autoretry mode. Drive LATCH high for
latched mode.
Circuit-Breaker Temperature Coefficient Selection Input. Drive TC low to select
a 3300ppm/°C temperature coefficient. Drive TC high to select a 0ppm/°C
temperature coefficient.
—
—
—
—
10, 11
EP
N.C.
EP
No Connection. Not internally connected.
Exposed Pad. Connect EP to GND.
_______________________________________________________________________________________
7
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
BACKPLANE
REMOVABLE CARD
1V TO V
CC
V
S
2.25V TO 13.2V
V
CC
R
20kΩ
R
SC
CB
CB
GATE SENSE OUT
SC_DET
V+
ON (ON*)
V
CC
GND
C
L
MAX5925
MAX5926
PGOOD**
EN (EN1**)
EN2**
EN
PGOOD (PGOOD*)
EN2
GND
SLEW
GND
TC** LATCH**
C
SLEW
*MAX5925A AND MAX5925C.
**MAX5926.
DC-DC CONVERTER
Figure 1. Typical Operating Circuit (Without R
)
SENSE
BACKPLANE
REMOVABLE CARD
R
SENSE
1V TO V
CC
V
S
2.25V TO 13.2V
V
CC
20kΩ
R
CB
CB
SENSE GATE
OUT
V+
ON (ON*)
V
SC_DET
CC
GND
C
L
MAX5924
MAX5926
PGOOD**
EN (EN1**)
EN2**
EN
PGOOD (PGOOD*)
EN2
GND
SLEW
GND
TC**
LATCH**
C
SLEW
V
CC
*MAX5924A AND MAX5924C.
**MAX5926.
DC-DC CONVERTER
Figure 2. Typical Operating Circuit (With R
)
SENSE
8
_______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
GATE
V
CC
CHARGE PUMP
MAX5924
MAX5925
MAX5926
2µA
N
SLEW
A
V
CC
R
LP
N
SC_DET
OUT
V
S
SLOW
COMPARATOR
V
V
CB,TH
CB
TIMER
R
CBF
0.2V
FAST
COMPARATOR
OSCILLATOR
CBF,TH
I
TC***
CB
PGOOD*
PGOOD**
LOGIC
SENSE
CONTROL
LATCH***
V
V
CC
1.24V
REF
EN/(EN1***)
V
CC
0.8V
CC
GND
1.24V
*MAX5924B, MAX5924D, MAX5925B, MAX5925D, MAX5926 ONLY.
**MAX5924A, MAX5924C, MAX5925A, MAX5925C, MAX5926 ONLY.
***MAX5926 ONLY.
EN2***
Figure 3. Functional Diagram
_______________________________________________________________________________________
9
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Detailed Description
V
RISES ABOVE
CC
The MAX5924/MAX5925/MAX5926 are hot-swap con-
troller ICs designed for applications where a line card is
inserted into a live backplane. Normally, when a line card
is plugged into a live backplane, the card’s discharged
filter capacitors provide a low impedance that can
momentarily cause the main power supply to collapse.
The MAX5924/MAX5925/MAX5926 are designed to
reside either in the backplane or in the removable card
to provide inrush current limiting and short-circuit pro-
tection. This is achieved using an external n-channel
MOSFET and an optional external current-sense resistor.
V
UVLO
AUTODETECT
R
SENSE
R
R
SENSE
ABSENT
SENSE
PRESENT
LOAD
PROBE*
SLEW-RATE-
LIMITED STARTUP
SUCCESS
FAILURE
Several critical parameters can be programmed:
• Slew rate (inrush current)
NORMAL
OPERATION
FAULT
MANAGEMENT
• Circuit-breaker threshold
*V
MUST REACH V
WITHIN t .
LP,TH LP
OUT
• Turn-on voltage
Figure 4. Startup Flow Chart
• Fault-management mode (MAX5926)
• Circuit-breaker temperature coefficient (MAX5926)
See the Selector Guide for a device-specific list of fac-
tory-preset features and parameters.
V
OUT
SR = dV
dt
SR = dV
dt
Startup Mode
The MAX5924/MAX5925/MAX5926 control an external
MOSFET connected in series with the hot-swapped
C
= SMALL
L
power supply, V . These devices hold the external
S
MOSFET off while the supply voltage, V , is below the
CC
V
LP,TH
(0.2V typ)
undervoltage lockout threshold or when the device is
V
OUT
disabled (see the EN (MAX5924/MAX5925, EN1/EN2
(MAX5926) section). When V
rises above V
and
CC
UVLO
C
= LARGE
L
I
INRUSH
the MAX5924/MAX5925/MAX5926 are enabled, an
undervoltage lockout timer initiates. V must remain
C
L
= SMALL
CC
greater than V
for t
to enter startup.
UVLO
D,UVLO
I
PROBE
I
LOAD
During the first stage of startup, the MAX5924/
MAX5925/MAX5926 detect whether an external sense
resistor is present and autoconfigure accordingly
(Figure 4). Bilevel fault protection temporarily disables,
and load-probing circuitry enables, if no sense resistor
is detected (see the Load Probing section). During load
I
LOAD
t
< t
PROBE LP
Figure 5. Startup Waveform
During startup, the MAX5924/MAX5925/MAX5926 gradu-
ally turn on the MOSFET, and V rises at a rate deter-
mined by the selected slew rate, SR (see the Slew Rate
section). The inrush current, I , is limited to a level
probing, if V
does not rise above V
within t
,
OUT
OUT
LP,TH
LP
the device manages the fault according to the selected
fault-management mode (see the Latched and
INRUSH
proportional to the load capacitance, C , and SR:
Autoretry Fault Management section). If V
rises
L
OUT
above V
within t , the MAX5924/MAX5925/
LP,TH
LP
I
(A) = C x 1000 x SR
L
INRUSH
MAX5926 begin startup (Figure 5). If an external
is detected, load probing is bypassed and
where SR is in V/ms and C is the load capacitance in
R
L
SENSE
Farads. For operation with and without R
GS
, once
bilevel fault protection enables with a startup circuit-
breaker programming current of I = 2 x I to
SENSE
V
exceeds V
, PGOOD and/or PGOOD assert
CB,EN
CB,SU
CB
and the MAX5924/MAX5925/MAX5926 enable standard
bilevel fault protection (see the Bilevel Fault Protection
section).
accommodate the higher-than-normal inrush current
required to charge board capacitance, C .
L
10 ______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
after it detects a large amplitude event such as a
short circuit.
Load Probing
The MAX5924/MAX5925/MAX5926 load-probing circuit-
ry detects short-circuit conditions during startup. As the
device begins load probing, SC_DET is connected to
In each case, when a fault is encountered, the power-
good output deasserts and the device drives GATE low.
After a fault, the MAX5924A, MAX5924B, MAX5925A,
and MAX5925B latch GATE low and the MAX5924C,
MAX5924D, MAX5925C, and MAX5925D enter the
autoretry mode. The MAX5926 has selectable latched or
autoretry modes. Figure 7 shows the slow comparator
response to an overcurrent fault.
V
through an internal switch with an on-resistance of
CC
R
(Figure 6). V
then charges the load with a probe
LP
CC
current:
I
= (V
- V
)/(R + R ) (Figure 1)
OUT LP SC
PROBE
CC
If the load voltage does not reach V
(0.2V, typ)
LP,TH
within t , a short-circuit fault is detected and the chan-
LP
nel is turned off according to the selected fault-manage-
ment mode (see the Fault Management section and
Figure 5). PGOOD/PGOOD asserts at the end of the
Bilevel Fault Protection
Bilevel Fault Protection in Startup Mode
Bilevel fault protection is disabled during startup when
startup period, t
, if no fault condition is present
START
no R
is detected. The device enables bilevel fault
SENSE
protection when R
(see the Turn-On Waveforms in the Typical Operating
Characteristics).
is detected, but the overcurrent
SENSE
trip levels are higher than normal during startup because
I = 2 x I (see the Startup Mode section).
CB,SU
Normal Operation
In normal operation, after startup is complete, protec-
tion is provided by turning off the external MOSFET
when a fault condition is encountered. Dual-speed/
bilevel fault protection incorporates two comparators
with different thresholds and response times to monitor
the current:
CB
Slow Comparator
The slow comparator is disabled during startup while
the external MOSFET turns on. This allows the
MAX5924/MAX5925/MAX5926 to ignore higher than
normal inrush currents charging the board capacitors
when a card is first plugged in.
1) Slow comparator. This comparator has a 1.6ms
(typ) response time. The slow comparator ignores
low-amplitude momentary current glitches. After an
extended overcurrent condition, a fault is acknowl-
edged and the MOSFET gate is discharged.
PGOOD*
2) Fast comparator. This comparator has a fixed
response time and a higher threshold voltage. The
fast comparator turns off the MOSFET immediately
PGOOD**
V
GATE
V
THPGOOD
14
12
10
8
4.3V TO 6.7V
V
OUT
I
LIM
6
I
LOAD
tCBS
V
= V
S
CC
4
*MAX5924B, MAX5924D, MAX5925B, MAX5925D, AND MAX5926 ONLY.
**MAX5924A, MAX5924C, MAX5925A, MAX5925C, AND MAX5926 ONLY.
2
4
6
8
10
12
14
V
(V)
CC
Figure 6. Load-Probe Resistance vs. Supply Voltage
Figure 7. Slow Comparator Response to an Overcurrent Fault
______________________________________________________________________________________ 11
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Table 1. Selecting Fault Management
Mode (MAX5926)
60
V
= 13.2V
CC
LATCH
Low
FAULT MANAGEMENT
Autoretry mode
Latched mode
50
40
30
20
10
0
High
Power-Good Outputs
The power-good output(s) are open-drain output(s) that
deassert:
• When V
< V
CC
UVLO
• During t
• When V < V
D,UVLO
GS
THPGOOD
3
4
0
1
2
5
6
7
• During load probing
V
(V)
GS
• When disabled (EN = GND (MAX5924/MAX5925),
EN1 = GND or EN2 = high (MAX5926))
Figure 8a. Gate Discharge Current vs. MOSFET Gate-to-Source
Voltage
• During fault management
• During t
or when latched off (MAX5924A,
RETRY
If the slow comparator detects an overload condition while
in normal operation (after startup is complete), it turns off
the external MOSFET by discharging the gate capaci-
MAX5924B, MAX5925A, MAX5925B, or MAX5926
(LATCH = low)).
PGOOD/PGOOD asserts only if the part is in normal
mode and no faults are present.
tance with I
. The magnitude of I
GATE,PD
GATE,PD
depends on the external MOSFET gate-to-source volt-
age, V . The discharge current is strongest immedi-
GS
ately following a fault and decreases as the MOSFET
gate is discharged (Figure 8a).
Undervoltage Lockout (UVLO)
UVLO circuitry prevents the MAX5924/MAX5925/
MAX5926 from turning on the external MOSFET until V
CC
. UVLO
exceeds the UVLO threshold, V
, for t
UVLO
D,UVLO
Fast Comparator
The fast comparator is used for serious current overloads
or short circuits. If the load current reaches the fast com-
parator threshold, the device quickly forces the MOSFET
off. The fast comparator has a response time of 280ns,
protects the external MOSFET from insufficient gate-drive
voltage, and t ensures that the board is fully
D,UVLO
plugged into the backplane and V
is stable prior to
CC
powering the hot-swapped system. Any input voltage
transient at V
below the UVLO threshold for more than
CC
and discharges GATE with I
(Figure 8a).
GATE,PD
the UVLO deglitch period, t , resets the device and ini-
DG
tiates a startup sequence. Device operation is protected
from momentary input-voltage steps extending below the
Latched and Autoretry Fault Management
The MAX5924A, MAX5924B, MAX5925A, and MAX5925B
latch the external MOSFET off when an overcurrent fault
is detected. Following an overcurrent fault, the
MAX5924C, MAX5924D, MAX5925C, and MAX5925D
enter autoretry mode. The MAX5926 can be configured
for either latched or autoretry mode (see Table 1).
UVLO threshold for a deglitch period, t
However, the
DG.
power-good output(s) may momentarily deassert if the
magnitude of a negative step in V exceeds approxi-
CC
mately 0.5V, and V
drops below V
. Operation is
CC
UVLO
unaffected and the power-good output(s) assert(s) within
200µs as shown in Figure 8b. This figure also shows that
In autoretry, a fault turns the external MOSFET off then
automatically restarts the device after the autoretry
if the UVLO condition exceeds t
= 900µs (typ), the
DG
power-good output(s) again deassert(s) and the load is
disconnected.
delay, t
. During the autoretry delay, pull EN or
RETRY
EN1 low to restart the device. In latched mode, pull EN
or EN1 low for at least 100µs to clear a latched fault
and restart the device.
12 ______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
V = V = 13.2V
S
CC
C
= 1µF
SLEW
C = 10µF
L
GATE
2V/div
1V/div
MOSFET ONLY
V
CC
5V/div
MOSFET AND
= 20nF
C
GATE
0V
0V
1V/div
PGOOD
200µs/div
10ms/div
Figure 8b. PGOOD Behavior with Large Negative Input-Voltage
Figure 9. Impact of C
on the V
Waveform
GATE
GATE
Step when V is Near V
S
S(MIN)
Determining Inrush Current
V
S
Determining a circuit’s inrush current is necessary to
choose a proper MOSFET. The MAX5924/MAX5925/
MAX5926 regulate the inrush current by controlling the
output-voltage slew rate, but inrush current is also a
function of load capacitance. Determine an anticipated
inrush current using the following equation:
R
CB
R
1
V
GATE
SENSE
OUT
CB
EN (EN1)
CC
dV
R
2
OUT
MAX5924_
MAX5925_
MAX5926
I
(A) = C
= C × SR × 1000
L
INRUSH
L
R
SC
dt
where C is the load capacitance in Farads, and SR is
L
SC_DET
(EN2)
the selected MAX5924/MAX5925/MAX5926 output slew
rate in V/ms. For example, assuming a load capaci-
tance of 100µF and using the value of SR = 10V/ms, the
anticipated inrush current is 1A. If a 16V/ms output slew
rate is used, the inrush current increases to 1.6A.
Choose SR so the maximum anticipated inrush current
does not trip the fast circuit-breaker comparator during
startup.
GND
(R + R ) V
EN/UVLO
2
1
( ) ARE FOR MAX5926 ONLY.
V
=
S,TURN-ON
R
2
Figure 10. Adjustable Turn-On Voltage
and the slew rate is slow (Figure 3). Figure 9 illustrates
how the addition of gate capacitance eliminates this ini-
Slew Rate
tial jump. C
should not exceed 25nF.
GATE
The MAX5924/MAX5925/MAX5926 limit the slew rate of
V
. Connect an external capacitor, C
, between
OUT
SLEW
EN (MAX5924/MAX5925),
EN1/EN2 (MAX5926)
SLEW and GND to adjust the slew-rate limit. Floating
SLEW sets the maximum slew rate to the default value.
The enable comparators control the on/off function of
the MAX5924/MAX5925/MAX5926. Enable is also used
to reset the fault latch in latch mode. Pull EN or EN1 low
for 100µs to reset the latch. A resistive divider between
Calculate C
using the following equation:
SLEW
C
SLEW
= 330 ♦ 10-9 / SR
where SR is the desired slew rate in V/ms.
EN or EN1, V , and GND sets the programmable turn-
S
A 2µA (typ) pullup current clamped to 1.4V causes an
on voltage to a voltage greater than V
(Figure 10).
UVLO
initial jump in the gate voltage, V
, if C
is small
GATE
GATE
______________________________________________________________________________________ 13
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
15,000
12,000
9000
6000
3000
0
15,000
12,000
9000
6000
3000
0
TC = 0ppm/°C
TC = 3300ppm/°C
V
V
V
= 1.5V
= 1.4V
= 1.3V
S
S
S
V
= 1.5V
S
V
V
V
V
V
= 1.4V
= 1.3V
= 1.2V
= 1.1V
= 1.0V
S
S
S
S
S
V
V
V
= 1.2V
= 1.1V
= 1.0V
S
S
S
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 11. Maximum Circuit-Breaker Programming Resistor vs. Temperature
Selecting a Circuit-Breaker Threshold
The MAX5924/MAX5925/MAX5926 offer a circuit-break-
er function to protect the external MOSFET and the load
from the potentially damaging effects of excessive cur-
I
LOAD
R
DS(ON)
rent. As load current flows through R
(Figure 12)
DS(ON)
V
V
S
OUT
or R
(Figure 13), a voltage drop is generated.
SENSE
After V
exceeds V
, the MAX5924/MAX5925/
CB,EN
GS
R
CB
MAX5926 monitor this voltage to detect overcurrent
conditions. If this voltage exceeds the circuit-breaker
threshold, the external MOSFET turns off and the
power-good output(s) deassert(s). To accommodate
different MOSFETs, sense resistors, and load currents,
CB GATE
SENSE OUT
SLOW
COMPARATOR
V
CB,TH
V
V
CB,OS
the MAX5924/MAX5925/MAX5926 voltage across R
CB
MAX5925
MAX5926
can be set between 10mV and 500mV. The value of the
circuit-breaker voltage must be carefully selected
based on V (Figure 11).
S
R
CBF
FAST
COMPARATOR
V
CBF,TH
No R
Mode
SENSE
CB,OS
I
CB
When operating without R
, calculate the circuit-
TC
SELECT
SENSE
breaker threshold using the MOSFET’s R
at the
DS(ON)
worst possible operating condition, and add a 20%
overcurrent margin to the maximum circuit current. For
example, if a MOSFET has an R
of 0.06Ω at T =
A
DS(ON)
+25°C, and a normalized on-resistance factor of 1.75 at
= +105°C, the R used for calculation is the
Figure 12. Circuit Breaker Using R
DS(ON)
T
A
DS(ON)
product of these two numbers, or (0.06Ω) x (1.75) =
0.105Ω. Then, if the maximum current is expected to be
2A, using a 20% margin, the current for calculation is
(2A) x (1.2) = 2.4A. The resulting minimum circuit-
breaker threshold is then a product of these two num-
bers, or (0.105Ω) x (2.4A) = 0.252V. Using this method
to choose a circuit-breaker threshold allows the circuit
to operate under worst-case conditions without causing
a circuit-breaker fault, but the circuit-breaker function
will still detect a short circuit or a gross overcurrent
condition.
To determine the proper circuit-breaker resistor value
use the following equation, which refers to Figure 12:
I
x R
(T) + V
DS(ON)
CB,OS
(
)
TRIPSLOW
R
=
CB
I
CB
where I
current.
is the desired slow-comparator trip
TRIPSLOW
14 ______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
I
LOAD
R
SENSE
V
V
50
45
40
35
30
25
20
S
OUT
V = V = 13.2V, R = 672Ω, I = 5A,
TRIPSLOW
S
CC
CB
R (25) = 6.5mΩ
DS(ON)
R
CB
CIRCUIT-BREAKER TRIP REGION
(V
≥ V
)
SENSE
CB
GATE
OUT
SLOW
CB
SENSE
V
CB,TH
COMPARATOR
V
V
CB,OS
CB,OS
MAX5925
MAX5926
R
CBF
V
= R
(T) x I
CB,OS
SENSE
DS(ON)
LOAD(MAX)
(4500ppm/°C)
FAST
V
CBF,TH
V
= I (T) x R + R
CB CB
CB
COMPARATOR
(3300ppm/°C)
I
CB
TC
-40
-15
10
35
60
85
110
SELECT
TEMPERATURE (°C)
Figure 13. Circuit Breaker Using R
Figure 14. Circuit-Breaker Trip Point and Current-Sense
Voltage vs. Temperature
SENSE
The fast-comparator trip current is determined by the
selected R value and cannot be adjusted indepen-
To determine the proper circuit-breaker resistor value,
use the following equation, which refers to Figure 12:
CB
dently. The fast-comparator trip current is given by:
I
x R
(
+ R
± V
CB,OS
)
CB
CB
CBF
R
I
x R
+ V
SENSE
CB,
(
)
TRIPSLOW
OS
I
=
TRIPFAST
R
=
(T)
CB
DS(ON)
I
CB
where I
current.
is the desired slow-comparator trip
R
Mode
TRIPSLOW
SENSE
When operating with R
, calculate the circuit-
SENSE
breaker threshold using the worst possible operating
conditions, and add a 20% overcurrent margin to the
maximum circuit current. For example, with a maximum
expected current of 2A, using a 20% margin, the cur-
rent for calculation is (2A) x (1.2) = 2.4A. The resulting
minimum circuit-breaker threshold is then a product of
The fast-comparator trip current is determined by the
selected R value and cannot be adjusted indepen-
dently. The fast-comparator trip current is given by:
CB
I
x R + R ± V
(
)
CB
CB
SENSE
CBF
CB,OS
I
=
TRIPFAST
R
this current and R
= 0.06Ω, or (0.06Ω) x (2.4A) =
SENSE
0.144V. Using this method to choose a circuit-breaker
threshold allows the circuit to operate under worst-case
conditions without causing a circuit-breaker fault, but
the circuit-breaker function will still detect a short-circuit
or a gross overcurrent condition.
Table 3. Suggested External MOSFETs
APPLICATION
PART
DESCRIPTION
CURRENT (A)
Table 2. Programming the Temperature
Coefficient (MAX5926)
International Rectifier
IRF7401
1
SO-8
2
5
Siliconix Si4378DY
SO-8
TC
TC
(ppm/°C)
ICB
Siliconix SUD40N02-06
Siliconix SUB85N02-03
DPAK
D2PAK
High
Low
0
10
3300
______________________________________________________________________________________ 15
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Applications Information
HIGH-CURRENT PATH
Component Selection
n-Channel MOSFET
Select the external n-channel MOSFET according to the
application’s current and voltage level. Table 3 lists some
SENSE RESISTOR
recommended components. Choose the MOSFET’s
on-resistance, R
, low enough to have a minimum
DS(ON)
voltage drop at full load to limit the MOSFET power dis-
sipation. High R can cause undesired power
R
CB
DS(ON)
loss and output ripple if the board has pulsing loads or
triggers an external undervoltage reset monitor at full
load. Determine the device power-rating requirement to
accommodate a short circuit on the board at startup
with the device configured in autoretry mode.
MAX5924
MAX5925
MAX5926
Figure 15. Kelvin Connection for the Current-Sense Resistor
Using the MAX5924/MAX5925/MAX5926 in latched mode
allows the consideration of MOSFETs with higher R
DS(ON)
Circuit-Breaker Temperature Coefficient
In applications where the external MOSFET’s on-resis-
tance is used as a sense resistor to determine overcur-
rent conditions, a 3300ppm/°C temperature coefficient
is desirable to compensate for the R
ture coefficient. Use the MAX5926’s TC input to select
the circuit-breaker programming current’s temperature
(see Table 2). The MAX5924 temper-
ature coefficient is preset to 0ppm/°C, and the
MAX5925’s is preset to 3300ppm/°C.
and lower power ratings. A MOSFET can typically with-
stand single-shot pulses with higher dissipation than the
specified package rating. Low MOSFET gate capaci-
tance is not necessary since the inrush current limiting is
achieved by limiting the gate dv/dt. Table 4 lists some
recommended manufacturers and components.
tempera-
DS(ON)
coefficient, TC
Be sure to select a MOSFET with an appropriate gate
drive (see the Typical Operating Characteristics).
ICB
Typically, for V
less than 3V or greater than 12V, select
CC
a 2.5V V MOSFET.
GS
Setting TC
to 3300ppm/°C allows the circuit-breaker
ICB
threshold to track and compensate for the increase in the
MOSFET’s R with increasing temperature. Most
MOSFETs have a temperature coefficient within a
3000ppm/°C to 7000ppm/°C range. Refer to the MOSFET
data sheet for a device-specific temperature coefficent.
Optional Sense Resistor
Select the sense resistor in conjunction with R to set
the slow and fast circuit-breaker thresholds (see the
Selecting a Circuit-Breaker Threshold section). The
sense-resistor power dissipation depends on the device
DS(ON)
CB
R
and I
are temperature dependent, and can
CB
configuration. If latched mode is selected, P
=
DS(ON)
RSENSE
(I
P
)2 x R
; if autoretry is selected, then
therefore be expressed as functions of temperature. At
a given temperature, the MAX5925/MAX5926 indicate
an overcurrent condition when:
OVERLOAD
SENSE
OVERLOAD
= (I
)2 x R
x (t /t
).
RSENSE
SENSE
ON RETRY
Choose a sense-resistor power rating of twice the
P
for long-term reliable operation. In addition,
RSENSE
I
x R
(T) ≥ I (T) x R + |V
|
TRIPSLOW
DS(ON)
CB
CB
CB,OS
ensure that the sense resistor has an adequate I2T rating
to survive instantaneous short-circuit conditions.
where V
is the worst-case offset voltage. Figure 14
CB,OS
graphically portrays operating conditions for a MOSFET
with a 4500ppm/°C temperature coefficient.
Table 4. Component Manufacturers
COMPONENT
MANUFACTURER
Dale-Vishay
IRC
PHONE
WEBSITE
402-564-3131
828-264-8861
888-522-5372
310-233-3331
www.vishay.com
www.irctt.com
Sense Resistors
Fairchild
www.fairchildsemi.com
www.irf.com
MOSFETs
International Rectifier
16 ______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Design Procedure
I
x R
+ V
CB,OS
(
TRIPSLOW
)
Given:
DS(ON)105
R
CB
=
• V
= V = 5V
S
I
CC
CB85
• C = 150µF
L
R
= ((6A x 8.58mΩ) + 4.7mV)/69.5µA = 808Ω
CB
• Full-Load Current = 5A
Layout Considerations
• No R
SENSE
Keep all traces as short as possible and maximize the
high-current trace dimensions to reduce the effect of
undesirable parasitic inductance. Place the MAX5924/
MAX5925/MAX5926 close to the card’s connector. Use
a ground plane to minimize impedance and induc-
tance. Minimize the current-sense resistor trace length
(<10mm), and ensure accurate current sensing with
Kelvin connections.
• I
= 500mA
INRUSH
Procedures:
1) Calculate the required slew rate and corresponding
C
SLEW
:
I
V
ms
INRUSH
SR =
= 3.3
1000 × C
L
When the output is short circuited, the voltage drop
across the external MOSFET becomes large. Hence, the
power dissipation across the switch increases, as does
the die temperature. An efficient way to achieve good
power dissipation on a surface-mount package is to lay
out two copper pads directly under the MOSFET pack-
age on both sides of the board. Connect the two pads
to the ground plane through vias, and use enlarged
copper mounting pads on the top side of the board.
−9
−9
330 × 10
330 × 10
C
=
=
= 0.1µF
SLEW
V
SR
3.3
ms
2) Select a MOSFET and determine the worst-case
power dissipation.
3) Minimize power dissipation at full load current and
at high temperature by selecting a MOSFET with an
appropriate R
. Assume a 20°C temperature
DS(ON)
It is important to maximize the thermal coupling between
the MOSFET and the MAX5925/MAX5926 to balance the
device junction temperatures. When the temperatures of
the two devices are equal, the circuit-breaker trip
threshold is most accurate. Keep the MOSFET and the
MAX5925/MAX5926 as close to each other as possible
to facilitate thermal coupling.
difference between the MAX5924/MAX5925/
MAX5926 and the MOSFET.
For example, at room temperature the IRF7822’s
R
= 6.5mΩ. The temperature coefficient for
DS(ON)
this device is 4000ppm/°C. The maximum R
DS(ON)
for the MOSFET at T
= +105°C is:
J(MOSFET)
ppm
°C
R
= 6.5mΩ × 1+ (105°C − 25°C) × 4000
DS(ON)105
Typical Operating Circuits
(continued)
= 8.58mΩ
The power dissipation in the MOSFET at full load is:
TYPICAL OPERATION WITH R
SENSE
BACKPLANE
REMOVABLE CARD
2
2
P = I R = (5A) × 8.58mΩ = 215mW
R
SENSE
D
N
V
1V TO V
OUT
CC
V
S
2.25V TO 13.2V
V
CC
4) Select R
.
CB
R
CB
Since the MOSFET’s temperature coefficient is
4000ppm/°C, which is greater than TC
(3300ppm/°C), calculate the circuit-breaker thresh-
old at high temperature so the circuit breaker is
guaranteed not to trip at lower temperature during
normal operation (Figure 15).
ICB
CB
OUT
SENSE GATE
V
CC
MAX5924
MAX5926
GND
GND
I
= I
+ 20% = 5A + 20% = 6A
TRIPSLOW
FULL LOAD
R
= 8.58mΩ (max), from step 2
DS(ON)105
I
= 58µA x (1 + (3300ppm/°C x (85 - 25)°C)
= 69.5µA (min)
CB85
SEE FIGURE 2 FOR A DETAILED TYPICAL OPERATING CIRCUIT WITH R
.
SENSE
______________________________________________________________________________________ 17
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Selector Guide
POWER-GOOD OUTPUT
CIRCUIT-BREAKER
TEMPCO
PART
FAULT MANAGEMENT
PGOOD
PGOOD
(ppm/°C)
(OPEN-DRAIN)
(OPEN-DRAIN)
MAX5924A
0
Latched
Latched
♦
—
♦
—
♦
—
♦
—
♦
—
♦
—
♦
—
♦
—
♦
♦
MAX5924B
MAX5924C
MAX5924D
MAX5925A
MAX5925B
MAX5925C
MAX5925D
MAX5926
0
0
Autoretry
0
Autoretry
3300
Latched
3300
3300
Latched
Autoretry
3300
Autoretry
0 or 3300 (Selectable)
Latched or Autoretry (Selectable)
Pin Configurations
TOP VIEW
V
CC
1
2
3
4
5
6
7
8
16 CB
SC_DET
EN1
15 SENSE
14 OUT
13 GATE
V
1
2
3
4
5
10 CB
CC
SC_DET
EN
9
8
7
6
SENSE
PGOOD
GND
MAX5924
MAX5925
OUT
MAX5926
12 SLEW
11 N.C.
10 N.C.
PGOOD (PGOOD)
GND
GATE
SLEW
EN2
PGOOD
LATCH
µMAX
9
TC
( ) FOR THE MAX5924A, MAX5924C, MAX5925A, AND MAX5925C.
QSOP-EP
Chip Information
TRANSISTOR COUNT: 3751
PROCESS: BiCMOS
18 ______________________________________________________________________________________
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
e
4X S
10
10
INCHES
MAX
MILLIMETERS
MAX
1.10
0.15
0.95
3.05
3.00
3.05
3.00
5.05
0.70
DIM MIN
MIN
-
A
-
0.043
0.006
0.037
0.120
0.118
0.120
0.118
0.199
A1
A2
D1
D2
E1
E2
H
0.002
0.030
0.116
0.114
0.116
0.114
0.187
0.05
0.75
2.95
2.89
2.95
2.89
4.75
0.40
H
0 0.50±0.1
0.6±0.1
L
0.0157 0.0275
0.037 REF
L1
b
0.940 REF
0.007
0.0106
0.177
0.270
0.200
1
1
e
0.0197 BSC
0.500 BSC
0.6±0.1
c
0.0035 0.0078
0.0196 REF
0.090
BOTTOM VIEW
0.498 REF
S
α
TOP VIEW
0°
6°
0°
6°
D2
E2
GAGE PLANE
A2
c
A
E1
b
L
α
A1
D1
L1
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 10L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0061
I
1
______________________________________________________________________________________ 19
1V to 13.2V, n-Channel Hot-Swap Controllers
Require No Sense Resistor
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information,
go to www.maxim-ic.com/packages.)
PACKAGE OUTLINE,
16L QSOP, .150" EXPOSED PAD
1
21-0112
C
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
20 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2004 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
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