General Description
The MAX5910/MAX5917 are fully integrated hot-swap
switches for positive supply rails. These devices allow
the safe insertion and removal of circuit cards into live
backplanes or ports without causing glitches on the
backplane power-supply rail. They also monitor various
circuit parameters and disconnect the load if a fault
condition occurs, alerting the host with a logic-level
IFAULT output. The MAX5910/MAX5917 operate over a
+10V to +65V input voltage range. They are designed
to permit hot plugging of an internet appliance such as
an IP phone but are not limited to that application.
During startup, an internal power FET regulates the cur-
rent between the backplane power source and the load
to 280mA for the MAX5910, 567mA for the MAX5917A,
and 420mA for the MAX5917B. After startup, the FET is
fully enhanced to reduce its on-resistance. To ensure
robust operation, the MAX5910/MAX5917 contain built-
in safety features that prevent damage to the internal
FET. They include an enable input, which responds to
positive logic signals (+3.3V or +5V), allowing the host
system to disconnect the load.
The MAX5910/MAX5917 Simple Swapper™ hot-swap ICs
monitor four parameters for fault conditions: undervoltage
lockout (UVLO), power-not-good, zero-current detection,
and thermal shutdown. These devices are available in the
extended temperature range, -40°C to +85°C. The
MAX5910 comes in an 8-pin SO package and the
MAX5917A/B is available in a 16-pin SO package.
Applications
IP Phones
Power-Over-LAN
Power-Over-MDI
Remote Power Distribution
Network Routers
Network Switches
Internet Appliances
Features
♦Provides Safe Hot Swap for +10V to +65V Power
Supplies
♦IEEE 802.3af Compliant (MAX5917A)
♦Startup into 500µF Load (MAX5917A)
♦280mA Current Limit for MAX5910
♦567mA Current Limit for MAX5917A
♦420mA Current Limit for MAX5917B
♦Zero-Current Load Detection
♦Integrated 2.2ΩPower FET
♦Status Output Reports Fault Conditions
♦Internal Switch-Protection Circuitry
♦Built-In Thermal Shutdown
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
________________________________________________________________ Maxim Integrated Products 1
+3.3V
IFAULT
VIN
VIN (+42V)
ENABLE
GND
VOUT
PGOOD
UVLO
10kΩ
10kΩ
MAX5910
MAX5917
L
O
A
D
ON
OFF
Typical Operating Circuit
Ordering Information
19-1706; Rev 0; 7/01
*Future product—contact factory for availability.
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.
PART TEMP. RANGE PIN-PACKAGE
MAX5910ESA -40°C to +85°C8 SO
MAX5917AESE* -40°C to +85°C 16 SO
MAX5917BESE -40°C to +85°C 16 SO
Simple Swapper is a trademark of Maxim Integrated Products, Inc.
Pin Configurations appear at end of data sheet.
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = +3.3V, and TA= -40°C to +85°C, unless otherwise noted. Typical values are
at TA= +25°C.)
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.
VIN, VOUT to GND................................................-0.3V to +70.0V
ENABLE to GND..................................................-0.3V to +12.0V
PGOOD, IFAULT to GND ....................................-0.3V to +12.0V
UVLO to GND ..............................................-0.3V to (VIN + 0.3V)
PGOOD, IFAULT Sink Current ............................................10mA
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)..................470mW
16-Pin SO (derate 12.9mW/°C above +70°C)............1039mW
Operating Temperature Range ...........................-40°C to +85°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering 10s) ..................................+300°C
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Voltage Range VIN 10 65 V
Supply Current IIN VIN = 10V to 65V (Note 1) 1.2 2.5 mA
MAX5910 250 280 310
MAX5917A 510 567 623
Output Current Limit ILIM VOUT = VIN - 5V,
VIN = 10V to 65V MAX5917B 370 420 470
mA
MAX5910 240
MAX5917A 400
Continuous Operating Output
Current IOUT (Note 2)
MAX5917B 350
mA
DMOS On-Resistance RDS
(
ON
)
VIN = 10V to 65V,
MAX5910, IOUT = 200mA
MAX5917A, IOUT = 400mA
MAX5917B, IOUT = 300mA
2.2 4 Ω
ENABLE Voltage Logic Low VLOW 0.8 V
ENABLE Voltage Logic High VHIGH 2.4 V
ENABLE High Input Current IIH VENABLE = +5V 1 µA
IFAULT Output Leakage Current IOH IFAULT = 10V, IOH > (IFTH + IFHYS)1µA
PGOOD Output Leakage
Current ILPGOOD PGOOD = 10V, VOUT > VPG 1µA
VIN to VOUT Leakage Current ILIN/OUT ENABLE = 0, VIN = +65V 1 µA
PGOOD/IFAULT Output Logic
Low VOL Sink current = 3mA 0.4 V
PGOOD Threshold VPG Percentage of VIN, VOUT rising 71 78 85 %
PGOOD Hysteresis PGHYS Percentage of VIN 10 %
MAX5910 2 12 25
MAX5917A 2 6 10
Zero-Current Detection
Threshold IFTH Decreasing output
current MAX5917B 2 12 25
mA
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
_______________________________________________________________________________________ 3
Note 1: Measured at GND pin at the end of the output voltage slew.
Note 2: Guaranteed by RDSON test. Limited by package power dissipation.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Zero-Current Detection
Threshold Hysteresis IFHYS Percentage of IFTH 10 %
IFAULT Output Delay tIFD (Figure 1) 7 12 17 ms
PGOOD Output Delay tPGD (Figure 2) 7 12 17 ms
Thermal Shutdown Temperature TJDie temperature increasing 140 oC
Thermal Shutdown Hysteresis TJHYS 3.5 oC
Default Undervoltage Lockout VUVLO VIN decreasing 24.5 26.5 28.5 V
Undervoltage Lockout
Hysteresis UVLOHYS Percentage of VUVLO 11 %
Minimum Undervoltage Lockout
Threshold
VUVLO
(MIN)
UVLO connected to VIN,
VIN decreasing 77.58 V
Undervoltage Lockout Input
Resistance RUVLO Force I = 5µA into UVLO pin 260 kΩ
ELECTRICAL CHARACTERISTICS (continued)
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = +3.3V, and TA= -40°C to +85°C, unless otherwise noted. Typical values are
at TA= +25°C.)
IOUT
IFAULT 3.3V
0
tIFD
IFTH
Figure 1.
IFAULT
Delay
tPGD
VPG
VIN
PGOOD
3.3V
0
Figure 2. Power-Good Delay
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
4 _______________________________________________________________________________________
Typical Operating Characteristics
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = 3.3V, RL= 1.8kΩ, TA= +25°C, unless otherwise noted).
2ms/div
MAX5910 TURN-ON WAVEFORMS
(RL = 1.8kΩ, CL = 0)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
A
0
C
B
MAX5910 toc04
0
0
2ms/div
MAX5910 TURN-OFF WAVEFORMS
(RL = 1.8kΩ, CL = 0)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc05
A
0
C
B
0
0
2ms/div
MAX5910 TURN-ON WAVEFORMS
(RL = 1.8kΩ, CL = 47µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc06
A
0
C
B
0
0
2010 60504030
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX5910 toc01
SUPPLY VOLTAGE (V)
SUPPLY CURRENT (mA)
0.4
0.8
0
1.6
2.0
1.2
NO LOAD
-15-40 603510 85
SUPPLY CURRENT
vs. TEMPERATURE
MAX5910 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
0.4
0.8
0
1.6
2.0
1.2
NO LOAD
-15-40 603510 85
ON-RESISTANCE vs. TEMPERATURE
MAX5910 toc03
TEMPERATURE (°C)
ON-RESISTANCE (Ω)
1.4
1.8
1.0
2.6
3.0
2.2
ILOAD = 150mA
2ms/div
MAX5917B TURN-ON WAVEFORMS
(RL = 1.8kΩ, CL = 0)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc10
A
0
C
B
0
0
2ms/div
MAX5917B TURN-OFF WAVEFORMS
(RL = 1.8kΩ, CL = 0)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc11
A
0
C
B
0
0
2ms/div
MAX5917B TURN-ON WAVEFORMS
(RL = 1Ω, CL = 47µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc12
A
0
C
B
0
0
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
_______________________________________________________________________________________ 5
Typical Operating Characteristics (continued)
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = 3.3V, RL= 1.8kΩ, TA= +25°C, unless otherwise noted).
20ms/div
MAX5910 TURN-OFF WAVEFORMS
(RL = 1.8kΩ, CL = 47µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc07
A
0
C
B
0
0
2ms/div
MAX5910 ZERO-CURRENT RESPONSE
A: IOUT, 100mA/div
B: IFAULT, 5V/div
C: VOUT, 20V/div
A
0
0
B
MAX5910 toc08
C
0
40ms/div
MAX5910 OVER-CURRENT RESPONSE
A: IOUT, 200mA/div
B: IFAULT, 5V/div
C: VOUT, 20V/div (SHORTED TO GND)
MAX5910 toc09
A
0
0
B
C
0
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
6 _______________________________________________________________________________________
40ms/div
MAX5917B OVER-CURRENT RESPONSE
A: IOUT, 200mA/div
B: IFAULT, 5V/div
C: VOUT, 20V/div (SHORTED TO GND)
MAX5910 toc17
A
0
0
B
C
0
250
260
280
270
290
300
-40 10-15 35 60 85
MAX5910 IOUT vs. TEMPERATURE
MAX5910 toc18
TEMPERATURE (°C)
IOUT (mA)
2ms/div
MAX5917B ZERO-CURRENT RESPONSE
A: IOUT, 100mA/div
B: IFAULT, 5V/div
C: VOUT, 20V/div
MAX5910 toc16
A
0
0
B
C
0
Typical Operating Characteristics (continued)
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = 3.3V, RL= 1.8kΩ, TA= +25°C, unless otherwise noted).
20ms/div
MAX5917B TURN-OFF WAVEFORMS
(RL = 1.8kΩ, CL = 47µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc13
A
0
C
B
0
0
10ms/div
MAX5917B TURN-ON WAVEFORMS
(RL = 300Ω, CL = 500µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc14
A
0
C
B
0
0
100ms/div
MAX5917B TURN-OFF WAVEFORMS
(RL = 300Ω, CL = 500µF)
A: ENABLE, 5V/div
B: VOUT, 20V/div
C: PGOOD, 5V/div
MAX5910 toc15
A
0
C
B
0
0
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
_______________________________________________________________________________________ 7
530
550
540
570
560
590
580
600
-40 10-15 35 60 85
MAX5917A IOUT vs. TEMPERATURE
MAX5910 toc20
TEMPERATURE (°C)
IOUT (mA)
0
100
50
200
150
300
250
350
00.80.4 1.2 1.6 2.0
MAX5910 IOUT vs. (VIN - VOUT)
MAX5910 toc21
VIN - VOUT (V)
IOUT (mA)
350
370
410
390
430
450
-40 10-15 35 60 85
MAX5917B IOUT vs. TEMPERATURE
MAX5910 toc19
TEMPERATURE (°C)
IOUT (mA)
0
100
300
200
400
500
00.80.4 1.2 1.6 2.0
MAX5917B IOUT vs. (VIN - VOUT)
MAX5910 toc22
VIN - VOUT (V)
IOUT (mA)
0
200
100
400
300
500
600
00.80.4 1.2 1.6 2.0
MAX5917A IOUT vs. (VIN - VOUT)
MAX5910 toc23
VIN - VOUT (V)
IOUT (mA)
Typical Operating Characteristics (continued)
(VIN = +42V, GND = 0, UVLO = open circuit, VENABLE = 3.3V, RL= 1.8kΩ, TA= +25°C, unless otherwise noted).
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
8 _______________________________________________________________________________________
Detailed Description
The MAX5910/MAX5917 are fully integrated hot-swap
switches for positive power-supply rails. The devices
allow safe insertion and removal of circuit cards into
live backplanes or ports without causing glitches on the
backplane power-supply rail. During startup these
devices act as current regulators using their on-board
FET to limit the amount of current drawn by the load to
280mA for MAX5910, 567mA for MAX5917A, and
420mA for MAX5917B. If the required load current
exceeds that current limit, the internal switch behaves
like a constant current source.
The MAX5910/MAX5917 monitor the input voltage, the
output voltage, the output current, and the die tempera-
ture. They assert IFAULT and PGOOD accordingly if
they detect an error condition.
A zero-current load detection feature activates if the
load current drops below IFTH for over 12ms. The
MAX5910/MAX5917 also include an ENABLE input
allowing the host system to turn the FET on or off.
Normal Operation
Startup
When power is first applied with ENABLE high, or when
ENABLE is asserted, the MAX5910/MAX5917A/
MAX5917B limit the current to the load to 280mA/
567mA/420mA. PGOOD is asserted high 12ms after the
output voltage exceeds the power-good threshold.
PGOOD is pulled low if VOUT is less than 70% VIN.
Zero-Current Load Fault
A zero-current load detection feature activates if the
load current drops below IFTH for more than 12ms. The
MAX5910/MAX5917 flag the zero-current condition but
do not disconnect the load. IFAULT is deasserted
whenever the load current exceeds the IFTH + IFHYS
zero-current detection threshold.
Undervoltage Lockout Fault
If VIN ≤UVLO, where UVLO is the desired voltage at
which the UVLO fault occurs, the internal FET is turned
off and IFAULT and PGOOD are pulled low. The default
UVLO voltage is 26.5V, but it can be adjusted using an
external resistive-divider (see the Changing the
Undervoltage Lockout Setting section).
Pin Description
PIN
MAX5910 MAX5917A/B NAME FUNCTION
1 2 UVLO
Undervoltage Lockout Input. Leave UVLO open circuit for the default
setting of 26.5V. Alternatively, UVLO can be connected to a resistive-
divider to set a desired lockout voltage. See the Changing the
Undervoltage Lockout Setting section.
23 V
IN Voltage Input Terminal. Bypass VIN to GND with a 0.1µF capacitor to
improve noise immunity.
3 1, 6, 8, 9, 15, 16 N.C. No Connection. Not internally connected.
4 7 ENABLE
3.3V Logic Input (TTL compatible), Active-High. Turns the internal FET
on or off. Drive ENABLE high to enable VOUT. Drive ENABLE low to
disable VOUT.
5 10 PGOOD
Open-Drain Logic Output, Active-High. PGOOD signals that the output
is within specification. When the output is less than 70% of the input, the
PGOOD signal is pulled low. Connect a 10kΩ pullup resistor (R) to 3.3V.
611IFAULT
Open-Drain Logic Output, Active-Low. IFAULT is asserted when the
output current falls below the IFTH nominal threshold or when the switch
is off. Connect a 10kΩ pullup resistor (R) to 3.3V.
7 4, 5, 12, 13 GND Ground
814 V
OUT Voltage Output Terminal
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
_______________________________________________________________________________________ 9
Thermal Shutdown Fault
The MAX5910/MAX5917 monitor their internal die tem-
perature. If the temperature of the die exceeds +140°C,
the internal FET is turned off and IFAULT and PGOOD
are pulled low. The output is enabled again only when
the die temperature is below the thermal shutdown tem-
perature by 3.5°C typically.
Power-Good (PGOOD)
Power-good (PGOOD) logic output signals when the
output has exceeded the PGOOD threshold. When the
output voltage is below 70% of the input voltage,
PGOOD is pulled low. When the output voltage is larger
than 80% of the input voltage for more than 12ms,
PGOOD is asserted.
Applications Information
Choosing a Device
The MAX5910 can output 280mA, the MAX5917B can
output 420mA, and the MAX5917A can output up to
567mA. In applications where high power is expected,
use the MAX5917 for its superior heat dissipation prop-
erties, and always solder all of its GND pins to a large
section of circuit board copper.
Logic Control
The enable input (ENABLE) responds to 3.3V logic sig-
nals and will force the internal FET off if ENABLE is
pulled low. This feature allows the host to disconnect
the load from the power bus if required. Drive ENABLE
high to enable VOUT.
Changing the Undervoltage Lockout
Setting
The undervoltage lockout (UVLO) value defaults to
26.5V if the UVLO pin is left open circuit (Figure 3).
Connect UVLO to VIN to set the undervoltage lockout to
a minimum of 7.5V (Figure 4). This lockout voltage can
also be changed with a resistive-divider from VIN to
GND. The center node of the divider is connected to
the UVLO pin (Figure 5). The values of R1 and R2 must
satisfy the condition R1//R2 << 260kΩand R2 <<
1.65MΩ. R2 can be calculated as follows:
R2 = R1 ✕[(VUVLO / 7.5V) - 1]
where VIN (UVLO) is the desired lockout voltage.
+3.3V
IFAULT
VIN
VIN
ENABLE
GND
VOUT
VOUT
N.C.
PGOOD
UVLO
R
R
MAX5910
+3.3V
VIN
VIN
ENABLE
GND
VOUT
VOUT
N.C.
PGOOD
UVLO
10kΩ
10kΩ
MAX5910
IFAULT
0.1µF
Figure 3. UVLO is Set Internally to its +26.5V Default Value
Figure 4. Minimum +7.5V UVLO Configuration
+3.3V
IFAULT
VIN
VIN
ENABLE
GND
VOUT
VOUT
N.C.
PGOOD
UVLO
10kΩ
R1
R2
10kΩ
MAX5910
0.1µF
Figure 5. Adjusting UVLO with an External Resistive-Divider
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
10 ______________________________________________________________________________________
CHARGE
PUMP
THERMAL
SHUTDOWN
CONTROL
LOGIC
BANDGAP
REFERENCE
UVLO
UVLO
1.236V
ON/OFF
ENABLE
IFAULT
PGOOD
RUV1
RUV2
RUV3
OSC.
VREF
IREG RPG1
RPG2
OUT
GND
PG
αVIN
VIN + 8V
RSENSE
GND
GND
IN
Functional Diagram
Pin Configurations
IFAULT
PGOODENABLE
1
2
8
7
VOUT
GNDVIN
N.C.
UVLO
8 SO
TOP VIEW
3
4
6
5
MAX5910
16
15
14
13
12
11
10
9
1
2
3
4
5
6
7
8
N.C. N.C.
N.C.
VOUT
GND
GND
IFAULT
PGOOD
N.C.
MAX5917A/B
16 SO
UVLO
VIN
N.C.
GND
GND
ENABLE
N.C.
MAX5910/MAX5917
+65V Simple Swapper Hot-Swap Switches
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 11
© 2001 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.
Package Information
SOICN.EPS
Chip Information
TRANSISTOR COUNT: 1003
PROCESS: SG3ISO
