MAX17612BATB+T [MAXIM]
4.5V to 60V, 250mA Current-Limiter with OV, UV, and Reverse Protection;
| 型号： | MAX17612BATB+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | 4.5V to 60V, 250mA Current-Limiter with OV, UV, and Reverse Protection |
| 文件： | 总21页 (文件大小：585K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
General Description
Benefits and Features
The Olympus series of ICs is the industry’s smallest
and robust integrated system protection solutions. The
MAX17612A/MAX17612B/MAX17612C adjustable over-
voltage and overcurrent protection devices are ideal to
protect systems against positive and negative input volt-
age faults up to +60V and -65V, and feature low 1.42Ω
● Robust Protection Reduces System Downtime
• Wide Input-Supply Range: +4.5V to +60V
• Hot Plug-in Tolerant Without TVS up to 35V Input
Supply
• Negative Input Tolerance to -65V
• Low R
1.42Ω (typ)
ON
• Reverse Current-Blocking Protection
• Thermal Overload Protection
• Extended -40°C to +125°C Temperature Range
(typ) R
FETs.
ON
The adjustable input overvoltage protection range is 5.5V
to 60V and the adjustable input undervoltage protec-
tion range is 4.5V to 59V. The input overvoltage-lockout
(OVLO) and undervoltage-lockout (UVLO) thresholds are
set using external resistors. Additionally, the devices offer
an internal input undervoltage threshold at 4.2V (typ).
• MAX17612A Enables OV, UV, and Reverse-Volt-
age Protection
• MAX17612B Enables OV and UV Protection
• MAX17612C Enables Reverse-Voltage Protection
The devices feature programmable current-limit protec-
tion up to 250mA; hence, controlling the inrush current at
startup while charging high capacitances at the output.
Current-limit threshold is programmed by connecting
a resistor from the SETI pin to GND. When the device
current reaches the programmed threshold, the device
prevents further increases in current by modulating the
FET resistance. The devices can be programmed to
behave in three different ways under current-limit con-
dition: Autoretry, Continous, or Latch-off modes. The
voltage appearing on the SETI pin is proportional to the
instantaneous current flowing through the device and is
read by an ADC.
● Flexible Design Options Enable Reuse and Less
Requalification
• Adjustable OVLO and UVLO Thresholds
• Programmable Forward-Current Limit: 10mA to
20mA with ±6% Accuracy and 20mA to 250mA with
±5% Accuracy Over Full Temperature Range
• Programmable Overcurrent Fault Response:
Autoretry, Continuous, and Latch-Off Modes
• Smooth Current Transitions
● Saves Board Space and Reduces External BOM
Count
• 10-Pin, 3mm x 3mm, TDFN-EP Package
• Integrated FETs
MAX17612A and MAX17612C block current flowing
in the reverse direction (i.e., from OUT to IN) whereas
MAX17612B allows current flow in the reverse direction.
The devices feature thermal shutdown protection against
excessive power dissipation.
The devices are available in a small, 10-pin (3mm x 3mm)
TDFN-EP package. The devices operate over the -40°C
to +125°C extended temperature range.
Ordering Information appears at end of data sheet.
Applications
● Sensor Systems
● Condition Monitoring
● Factory Sensors
● Process Instrumentation
● Weighing and Batching Systems
● Industrial Applications such as PLC, Network-Control
Modules, Battery-Operated Modules
19-100363; Rev 0; 6/18
MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Typical Operating Circuits
MAX17612A and MAX17612B
IN
OUT
0.47µF
4.7µF
V
PULLUP
MAX17612A
MAX17612B
SYSTEM
R3
SYSTEM
POWER
SUPPLY
FLAG
UVOV
EN
FAULT
OPTIONAL
FOR
HIGH
INPUT
SURGE
OVLO
UV/OV FAULT
R1
R2
UVLO
EN
APPLICATIONS
R4
CLMODE
SETI
ADC
GND
R
SETI
MAX17612C
IN
OUT
0.47µF
4.7µF
V
PULLUP
SYSTEM
MAX17612C
FORWARD
FAULT
REVERSE
FAULT
SYSTEM
POWER
SUPPLY
FWD
REV
EN
OPTIONAL
FOR
HIGH
INPUT
SURGE
APPLICATIONS
EN
CLMODE
SETI
ADC
GND
R
SETI
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Absolute Maximum Ratings
IN to GND...............................................................-70V to +65V
IN to OUT...............................................................-65V to +65V
OUT to GND .........................................................-0.3V to +65V
SETI to GND (Note 1)..........................................-0.3V to +1.6V
Continuous Power Dissipation (10 pin TDFN-EP
(T = +70°C, derate 24.4mW/°C above +70°C)) ...1951.2mW
A
UVLO, OVLO to GND .............-0.3V to MAX(V , V
UVOV, FLAG, FWD, REV, EN,
CLMODE to GND.............................................-0.3V to +6.0V
IN Current (DC) .............................................................262.5mA
) + 0.3V
Extended Operating Temperature Range ...........-40°C to 125°C
Junction Temperature Range (Note 2)............. -40°C to +150°C
Storage Temperature Range............................ -65°C to +150°C
Lead Temperature (Soldering, 10s).................................+300°C
IN OUT
Note 1: SETI pin is internally clamped. Forcing more than 5mA current into the pin can damage the device.
Note 2: Junction temperature greater than +125°C degrades operating lifetimes.
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.
Package Information
PACKAGE TYPE: 12 TDFN
Package Code
T1033+1C
21-0137
90-0003
Outline Number
Land Pattern Number
THERMAL RESISTANCE, FOUR-LAYER BOARD:
Junction to Ambient (θ
)
41°C/W
9°C/W
JA
Junction to Case (θ
)
JC
For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a “+”,
“#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing
pertains to the package regardless of RoHS status.
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board.
For detailed information on package thermal considerations, refer to www.maximintegrated.com/thermal-tutorial.
Electrical Characteristics
(V = +4.5 to +60V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V = +24V, T = +25°C, R
= 1.2kΩ.)
IN
A
IN
A
SETI
(Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
IN Voltage Range
V
4.5
60
60
2
IN
Shutdown Input Current
Shutdown Output Current
Reverse Input Current
Supply Current
I
V
V
V
V
V
V
= 0V
25
< 1
μA
SHDN
EN
I
= 0V, V
= 0V
-2
µA
OFF
EN
OUT
I
= -60V, V = 0V
OUT
-85
-50
µA
IN_RVS
IN
IN
IN
IN
I
= 24V, V = 5V
EN
0.89
4.22
3.5
1.21
4.50
mA
IN
rising
3.46
1.45
Internal Undervoltage-Trip
Level
V
V
UVLO
falling
UVLO, OVLO Reference
V
1.50
1.55
100
V
REF
UVLO, OVLO Threshold
Hysteresis
3.3
%
V
= V
= 0 to 2V.
UVLO
OVLO
UVLO, OVLO Leakage Current
I
-100
nA
LEAK
(MAX17612A, MAX17612B only)
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Electrical Characteristics (continued)
(V = +4.5 to +60V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V = +24V, T = +25°C, R
= 1.2kΩ.)
IN
A
IN
A
SETI
(Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
5.5
4.5
3.0
TYP
MAX
UNITS
OVLO Adjustment Range
UVLO Adjustment Range
Internal POR
(Note 4)
(Note 4)
60
59
V
V
V
4.3
INTERNAL FETs
Internal FETs On-Resistance
Current-Limit Adjustment Range
R
I
= 100mA, V ≥ 8V
1.42
2.7
250
+6
Ω
ON
LOAD
IN
I
(Note 5)
10mA < I
20mA < I
10
-6
-5
mA
LIM
< 20mA
LIM
LIM
Current-Limit Accuracy
%
≤ 250mA
+5
FLAG Assertion Drop-Voltage
Threshold
Increase (V - V
asserts, V = 24V, I = 10mA
IN IN
) drop until FLAG
IN
OUT
V
370
2
470
11
570
20
mV
mV
μs
FA
Reverse Current-Blocking
Slow Threshold
(V
- V ). (MAX17612A,
OUT IN
V
RIBS
MAX17612C only)
Reverse Current-Blocking
Debounce Blanking Time
t
(MAX17612A, MAX17612C only)
100
14.4
70
140
16.0
105
150
180
17.6
140
230
DEBRIB
Reverse Current-Blocking
Powerup Blanking Time
t
(MAX17612A, MAX17612C only)
ms
mV
ns
BLKRIB
Reverse Current-Blocking
Fast Threshold
(V
-V ). (MAX17612A,
OUT IN
V
RIBF
MAX17612C only)
I = 2.5A, (MAX17612A,
REVERSE
Reverse Current-Blocking
Fast-Response Time
t
RIB
MAX17612C only) (Note 6)
Current into OUT when (V
> 130mV. (MAX17612A, MAX17612C
only)
- V
OUT
IN)
Reverse-Blocking Supply
Current
I
0.89
1.25
mA
RBL
SETI
R
× I
V
1.5
200
200
V
SETI
LIM
RI
10mA ≤ I
20mA ≤ I
≤ 20mA
190
193
1.6
210
207
2.2
0.1
OUT
Current-Mirror Output Ratio
C
A/A
IRATIO
≤ 250mA
OUT
Internal SETI Clamp
SETI Leakage Current
LOGIC INPUT
5mA into SETI
= 1.6V
V
V
-0.1
μA
SETI
EN Input-Logic High
EN Input-Logic Low
EN Pullup Voltage
V
1.4
V
V
IH
V
0.4
2
IL
EN pin unconnected. V = 60V
1.3
60
V
IN
EN Input Current
V
= 5.5V
= 0.4V
92
μA
μA
V
EN
EN
EN Pullup Current
V
1.0
2.0
0.25
8
3.0
3.8
0.60
10
8.0
4.9
0.95
12
CLMODE Input-Logic High
CLMODE Input-Logic Low
CLMODE Pullup Input Current
V
µA
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Electrical Characteristics (continued)
(V = +4.5 to +60V, T = -40°C to +125°C, unless otherwise noted. Typical values are at V = +24V, T = +25°C, R
= 1.2kΩ.)
IN
A
IN
A
SETI
(Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
FLAG, UVOV, FWD, REV OUTPUTs
FLAG, UVOV, FWD, REV
Output-Logic Low Voltage
I
= 1mA
0.4
1
V
SINK
V
= V
= V
= V
= V
IN
FLAG
UVOV
FWD REV
FLAG, UVOV, FWD, REV
Output-Leakage Current
μA
= 5.5V. FLAG, UVOV, FWD and REV
pins are deasserted
TIMING CHARACTERISTICS
t
V
R
= 24V, R
= 1kΩ, C
= 0pF,
ON_
IN
LOAD
LOAD
Switch Turn-On Time
230
0.46
20
450
µs
µs
μs
= 1.2kΩ
SWITCH
SETI
Overvoltage Switch Turn-Off
Time
V
exceeds V
as a step;
REF
OVLO
t
0.65
OFF_OVP
R
= 1kΩ
LOAD
Overvoltage Falling-Edge
Debounce Time
t
DEB_OVP
OCP_RES
I
= 0.25A, C
= 0, I
step
LIM
LOAD
OUT
Overcurrent Protection
Response Time
t
from 0.125A to 0.375A. Time to regulate
100
16
μs
I
to current limit.
OUT
From V
and EN = High to V
< V < V
IN IN_OVLO
IN_UVLO
IN Debounce Time
t
= 10% of V .
14.4
17.6
ms
DEB
OUT
IN
Elapses only at power-up.
Current-Limit Smooth-Transition
Time
t
100
40
μs
ms
ms
REF_RAMP
Current-Limit Blanking Time
t
36
44
BLANK
After blanking time from I
FLAG deasserted (Note 7)
> I
to
OUT
LIM
Current-Limit Autoretry Time
t
540
600
660
RETRY
THERMAL PROTECTION
Thermal Shutdown
T
160
28
°C
°C
J
Thermal Shutdown Hysteresis
T
J(HYS)
Note 3: All devices are 100% production tested at T = +25°C. Limits over the operating-temperature range are guaranteed by
A
design; not production tested.
Note 4: User settable. See the Overvoltage Lockout (OVLO) and Undervoltage Lockout (UVLO) sections for instructions.
Note 5: The current limit can be set below 100mA with a decresed accuracy.
Note 6: Guaranteed by design; not production tested.
Note 7: The ratio between autoretry time and blanking time is fixed and equal to 15.
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Typical Operating Characteristics
(CIN = 0.47μF, COUT = 4.7μF, TA = +25°C, unless otherwise noted.)
IN SUPPLY CURRENT
IN SUPPLY CURRENT
NORMALIZED ON-RESISTANCE
vs. SUPPLY VOLTAGE
vs. SUPPLY VOLTAGE
vs. TEMPERATURE
toc01
toc02
toc03
1.00
0.95
0.90
0.85
0.80
0.75
0.70
1.00
0.98
0.95
0.93
0.90
0.88
0.85
0.83
0.80
1.10
1.05
1.00
0.95
0.90
NORMALIZED TO
VIN = 24V
IOUT = 100mA
SETI UNCONNECTED
SETI UNCONNECTED
TA = +125°C
TA = +25°C
TA = -40°C
-50 -25
0
25
50
75 100 125 150
4
12
20
28
36
44
52
60
4
12
20
28
36
44
52
60
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
SUPPLY VOLTAGE (V)
NORMALIZED CURRENT LIMIT
vs. SUPPLY VOLTAGE
NORMALIZED CURRENT LIMIT
vs. TEMPERATURE
NORMALIZED ON-RESISTANCE
vs. TEMPERATURE
toc04
toc06
toc05
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
NORMALIZED TO
VIN = +24V
RSETI = 1.5kΩ
NORMALIZED TO
TA = +25oC
NORMALIZED TO
TA = +25°C
RSETI = 1.5kΩ
-50 -25
0
25
50
75 100 125 150
-50 -25
0
25
50
75 100 125 150
4
12
20
28
36
44
52
60
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
TEMPERATURE (°C)
NORMALIZED UVLO THRESHOLD
vs. TEMPERATURE
NORMALIZED OVLO THRESHOLD
vs. TEMPERATURE
CURRENT LIMIT vs. RSETI
toc08
toc09
toc07
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
1.05
1.04
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
0.25
0.20
0.15
0.10
0.05
0.00
NORMALIZED TO
TA = +25°C
NORMALIZED TO
TA = +25oC
-50 -25
0
25
50
75 100 125 150
-50 -25
0
25
50
75 100 125 150
0
5
10
15
20
25
30
RSETI (kΩ)
TEMPERATURE (°C)
TEMPERATURE (°C)
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Typical Operating Characteristics (continued)
(CIN = 0.47μF, COUT = 4.7μF, TA = +25°C, unless otherwise noted.)
SWITCH DEBOUNCE TIME
vs. TEMPERATURE
SHUTDOWN REVERSE CURRENT
vs. TEMPERATURE
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
toc10
toc11
toc12
-10
-12
-14
-16
-18
-20
-22
-24
-26
-28
-30
50
45
40
35
30
25
20
15
10
5
17.0
16.6
16.2
15.8
15.4
15.0
VIN = -24V
VIN = +24V
EN = LOW
EN = LOW
OUT = GND
OUT = GND
0
-50 -25
0
25
50
75 100 125 150
-50 -25
0
25
50
75 100 125 150
-50 -25
0
25
50
75 100 125 150
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
SWITCH TURN-OFF TIME
vs. TEMPERATURE
REVERSE-BLOCKING RESPONSE
POWER-UP RESPONSE
toc13
toc14
toc15
20
18
16
14
12
10
8
EN TRANSITION TO IOUT FALLING
TO 10% OF INITIAL VALUE
RL = 240Ω
24V
20V/div
20V/div
VIN
VIN
20V/div
20V/div
35V
VOUT
24V
VOUT
VUVOV
5V/div
VFLAG
5V/div
1A/div
6
4
IIC
200mA/div
IIC
2
0
-50 -25
0
25
50
75 100 125 150
4ms/div
4µs/div
TEMPERATURE (°C)
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Typical Operating Characteristics (continued)
(CIN = 0.47μF, COUT = 4.7μF, TA = +25°C, unless otherwise noted.)
OUTPUT SHORT-CIRCUIT RESPONSE
CURRENT-LIMIT RESPONSE
toc16
toc17
VIN
20V/div
20V/div
VIN
20V/div
20V/div
ILIM = 0.25A
VOUT
VOUT
5V/div
VFLAG
VFLAG
5V/div
ILIM = 0.25A,
IL = 0mA TO SHORT ON OUT WITH 1A/s
IOUT
200mA/div
IOUT
200mA/div
10ms/div
100ms/div
CURRENT SENSE RATIO
vs. OUTPUT CURRENT
AUTORETRY TIME (tRETRY
)
toc18
toc19
205
204
203
202
201
200
199
198
197
196
195
VIN
20V/div
20V/div
AUTORETRY MODE
ILIM = 0.25A
VOUT
VFLAG
5V/div
IOUT
200mA/div
0
25 50 75 100 125 150 175 200 225 250
OUTPUT CURRENT (mA)
200ms/div
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Pin Configurations
MAX17612A and MAX17612B
TOP VIEW
IN
1
2
3
4
5
10 OUT
UVLO
OVLO
9
8
GND
SETI
MAX17612A
MAX17612B
CLMODE
EN
7
UVOV
FLAG
6
*EP
TDFN-EP
*CONNECT EP TO GND
MAX17612C
TOP VIEW
IN
NC
1
2
3
4
5
10
9
OUT
GND
SETI
REV
FWD
NC
8
MAX17612C
CLMODE
EN
7
6
*EP
TDFN-EP
*CONNECT EP TO GND
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Pin Description
PIN
NAME
FUNCTION
MAX17612A
MAX17612B
MAX17612C
Input Pins. Connect a low-ESR ceramic capacitor to GND. For Hot Plug-In applications,
see the Applications Information section.
1
1
IN
UVLO Adjustment. Connect resistive potential divider from IN to GND to set the UVLO
threshold.
2
—
3
—
2-3
—
UVLO
N.C.
Not Connected. Leave unconnected.
OVLO Adjustment. Connect resistive potential divider from IN to GND to set the OVLO
threshold.
OVLO
Current-Limit Mode Selector. Connect CLMODE to GND for Continuous mode.
4
5
4
5
CLMODE Connect a 150kΩ resistor between CLMODE and GND for Latch-off mode. Leave
CLMODE unconnected for Autoretry mode.
EN
Active-High Enable Input. Internally pulled up to 1.8V.
Open-Drain, Fault Indicator Output. FLAG goes low when:
•
•
•
•
Overcurrent duration exceeds the blanking time.
Reverse current is detected (MAX17612A only).
Thermal shutdown is active.
6
—
FLAG
R
SETI
is less than 1kΩ (max).
Open-Drain, Fault Indicator Output. FWD goes low when:
•
•
•
Overcurrent duration exceeds the blanking time.
Thermal shutdown is active.
—
7
6
FWD
R
SETI
is less than 1kΩ (max).
Open-Drain, Fault Indicator Output. UVOV goes low when:
•
•
—
UVOV
Input voltage falls below UVLO threshold.
Input voltage rises above OVLO threshold.
—
8
7
8
REV
SETI
GND
OUT
Open-Drain, Fault Indicator Output. REV goes low when reverse current is detected.
Overcurrent Limit Adjustment Pin and Current Monitoring Output. Connect a resistor from
SETI to GND to set overcurrent limit. See the Setting Current-Limit Threshold section.
9
9
Ground.
Output Pins. For a long output cable or inductive load, see the Applications Information
section.
10
10
Exposed Pad. Connect EP to a large GND plane with several thermal vias for best
thermal performance. Refer to the MAX17612A EV kit data sheet for a reference layout
design.
—
—
EP
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Functional Diagrams
MAX17612A-MAX17612B
IN
OUT
I
FET
Q2
Q1
I
/C
FET IRATIO
CURRENT
REGULATION
I
/C
FET IRATIO
SETI
HV FET
CONTROL
1.5V
REVERSE
PROTECTION
UVOV
FLAG
(MAX17612A ONLY)
1.5V
OVLO
CONTROL
LOGIC
1.5V
1.8V
UVLO
CLMODE
EN
THERMAL
SHUTDOWN
GND
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Functional Diagrams (continued)
MAX17612C
IN
OUT
I
Q2
FET
Q1
I
/C
FET IRATIO
CURRENT
REGULATION
I
/C
FET IRATIO
SETI
HV FET
CONTROL
1.5V
REV
REVERSE
PROTECTION
FWD
CONTROL
LOGIC
1.8V
CLMODE
EN
THERMAL
SHUTDOWN
GND
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Operating Circuits to adjust the UVLO threshold voltage.
Use the following equation to adjust the UVLO threshold.
The recommended value of R1 is 2.2MΩ.
Detailed Description
The MAX17612A/MAX17612B/MAX17612C overvoltage-
and overcurrent-protection devices offer adjustable pro-
tection boundaries for systems against input positive and
negative faults up to +60V and -65V, and output load cur-
rent up to 1A. The devices feature two internal MOSFETs
R1
R2
V
= V
× 1+
UVLO
REF
where V
= 1.5V.
REF
connected in series with a low cumulative R
of 1.42mΩ
ON
(typ).The devices block out negative input voltages com-
pletely. Input undervoltage protection can be programmed
between 4.5V and 59V, while the overvoltage protection
can be independently programmed between 5.5V and
60V. Additionaly, the devices have an internal default
undervoltage lockout set at 4.2V (typ).
All three devices have an input UVLO threshold set at
4.2V (typ). MAX17612C has no UVLO pin to adjust the
UVLO threshold voltage externally.
Overvoltage Lockout (OVLO)
MAX17612A and MAX17612B devices have an OVLO
adjustment range from 5.5V to 60V. Connect an external
resistive potential divider to the OVLO pin as shown in the
Typical Operating Circuits to adjust the OVLO threshold
voltage. Use the following equation to adjust the OVLO
threshold. The recommended value of R3 is 2.2MΩ.
The devices are enabled or disabled through the EN pin
by a master supervisory system; hence, offering a switch
operation to turn on or turn off power delivery to con-
nected load.
The current through the devices is limited by setting a cur-
rent limit, which is programmed by a resistor connected
from SETI to GND. The current limit can be programmed
between 10mA to 250mA. When the device current
reaches or exceeds the set current limit, the on-resistance
of the internal FETs are modulated to limit the current to
set limits. The devices offer three different behavioral
models when under current limited operations: Autoretry,
Continuous, and Latch-Off modes. The SETI pin also
presents a voltage with reference to GND, which under
normal operation is proportional to the device current. The
voltage appearing on the SETI pin is read by an ADC on
the monitoring system for recording instantaneous device
current. To avoid oscillation, do not connect more than
10pF to the SETI pin.
R3
R4
V
= V
× 1+
OVLO
REF
where V
= 1.5V.
REF
The MAX17612C device has no OVLO pin to adjust the
OVLO threshold voltage.
The OVLO reference voltage (V
) is set at 1.5V. If the
REF
voltage at the OVLO pin exceeds V
for time equal
REF
to the overvoltage switch turn-off time (t
switch is turned off and UVOV is asserted. When the
OVLO condition is removed, the device takes the over-
), the
OFF_OVP
voltage falling-edge debounce time (t
) to start
DEB_OVP
the switch turn-on process. The switch turns back on after
switch turn-on time (t
) and UVOV is deas-
ON_SWITCH
serted. Figure 1 depicts typical behavior in overvoltage
conditions.
The devices offer communication signals to indicate
different operational and fault signals. MAX17612A
and MAX17612B offer FLAG and UVOV signals, while
MAX17612C offers FWD and REV signals. All commu-
nication signal pins are open drain in nature and require
external pullup resistors to appropriate system interface
voltage.
tOFF_OVP
tDEB_OVP
tON_SWITCH
1.5V
MAX17612A and MAX17612C block reverse current flow
(from OUT to IN) while MAX17612B allows reverse current
flow.
OVLO
SWITCH
STATUS
All three devices offer internal thermal shutdown protection
against excessive power dissipation.
UVOV
Undervoltage Lockout (UVLO)
TIME
NOTE: TIME NOT IN SCALE
MAX17612A and MAX17612B have a UVLO adjustment
range from 4.5V to 59V. Connect an external resistive
potential divider to the UVLO pin as shown in the Typical
Figure 1. Overvoltage-Fault Timing Diagram
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Input Debounce Protection
V
(V)
SETI
I
(A) =
IN−OUT
The devices feature input debounce protection. The
devices start operation (turn on the internal FETs) only
if the input voltage is higher than UVLO threshold for a
R
(kΩ)
SETI
If SETI is left unconnected, V
≥ 1.5V. The current
SETI
regulator does not allow any current to flow. During
period greater than the debounce time (t
). The t
DEB
DEB
startup, this causes the switches to remain off and FLAG
elapses only at power-up of the devices. This feature is
intended for applications where the EN signal is present
when the power supply ramps up. Figure 2 depicts a typi-
cal debounce timing diagram.
(or FWD) to assert after t
elapses. During startup,
BLANK
270μA current is forced to flow through R
. If the volt-
SETI
age at SETI is below 150mV, the switches remain off and
FLAG (or FWD) asserts.
Enable
Current-Limit Type Select
The CLMODE pin is used to program the overcurrent
response of the devices in one of the following three modes:
The devices are enabled or disabled through the EN pin
by driving it above or below the EN threshold voltage.
Hence the devices can be used to turn on or off power
delivery to connected loads using the EN pin.
Autoretry mode (CLMODE pin is left unconnected),
Continuous mode (CLMODE pin is connected to GND),
Latch-off mode (a 150kΩ resistor is connected between
CLMODE and GND).
Setting Current-Limit Threshold
Connect a resistor between SETI and GND to program
the current-limit threshold in the devices. Use the following
equation to calculate current-limit setting resistor:
Table 1. Current-Limit Threshold
vs. SETI-Resistor Values
300
R
(kΩ) =
SETI
I
(mA)
LIM
R
(kΩ)
CURRENT LIMIT (mA)
SETI
where I
is the desired current limit in mA.
LIM
30
10
25
Do not use a R
current-limit thresholds for different resistor values.
smaller than 1.5kΩ. Table 1 shows
SETI
12
6
50
The devices feature read-out of the current flowing into
3
100
150
200
250
the IN pin. A current mirror, with a ratio of C
, is
IRATIO
implemented, using a current-sense auto-zero opera-
tional amplifier. The mirrored current flows out through
the SETI pin, into the external current-limit resistor. The
voltage on the SETI pin provides information about the IN
current with the following relationship:
2
1.5
1.2
<tDEB
<tDEB
tDEB
OVLO
UVLO
VIN
ON
OFF
SWITCH
STATUS
TIME
NOTE: TIME NOT IN SCALE
Figure 2. Debounce Timing Diagram
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Autoretry Current Limit
Continuous Current Limit
In autoretry current-limit mode, when current through the
In continuous current-limit mode, when current through
the device reaches the current limit threshold, the device
limits output current to the programmed current limit.
The FLAG (or FWD) pin asserts if overcurrent condition
device reaches the current-limit threshold, the t
BLANK
timer begins counting. The FLAG (or FWD) pin asserts if
the overcurrent condition is present for t . The timer
BLANK
resets if the overcurrent condition resolves before t
is present for t
and deasserts when the overload
BLANK
BLANK
has elapsed. A retry time delay (t
) starts immedi-
condition is removed. Figure 4 depicts typical behavior in
the continuous current-limit mode.
RETRY
ately after t
has elapsed. During t
time, the
BLANK
RETRY
switch remains off. Once t
has elapsed, the switch
RETRY
is turned back on again. If the fault still exists, the cycle
is repeated and FLAG (or FWD) pin remains asserted. If
the overcurrent condition is resolved, the switch stays on.
CONTINUOUS MODE
tBLANK
The autoretry feature reduces system power in case of
overcurrent or short-circuit conditions. When the switch
OUT
is on during t
time, the supply current is held at
BLANK
the current limit. During t
time, there is no current
RETRY
DEVICE COMES OUT OF
through the switch. Thus, output current is much less
than the programmed current limit. Calculate the average
output current using the following equation:
THERMAL SHUTDOWN MODE
CURRENT LIMIT
LOAD CURRENT
DEVICE GOES TO
THERMAL SHUTDOWN MODE
t
BLANK
I
= I
LIM
LOAD
FLAG
(OR FWD)
t
+ t
RETRY
BLANK
With a 40ms (typ) t
and 600ms (typ) t
, the
RETRY
BLANK
TIME
duty cycle is 6.25%, resulting in a 93.75% power reduc-
tion when compared to the switch being on the entire
time. Figure 3 depicts typical behavior in the autoretry
current-limit mode.
NOTE: TIME NOT IN SCALE
Figure 4. Continuous Fault-Timing Diagram
AUTORETRY MODE
tRETRY
tBLANK
tRETRY
tBLANK
tBLANK
tRETRY
OUT
DEVICE COMES OUT OF
THERMAL SHUTDOWN MODE
CURRENT LIMIT
LOAD CURRENT
DEVICE GOES TO
THERMAL SHUTDOWN MODE
FLAG
(OR FWD)
TIME
NOTE: TIME NOT IN SCALE
Figure 3. Autoretry Fault-Timing Diagram
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
time, the device monitors the voltage difference between
the OUT and IN pins to determine whether the reverse
current is still present. Once the reverse current condition
has been removed, Q1 is turned back on and the FLAG
Latch-Off Current Limit
In latch-off current-limit mode, when current through the
device reaches the current-limit threshold, the t
timer begins counting. The FLAG (or FWD) pin asserts if
an overcurrent condition is present for t . The timer
resets when the overcurrent condition disappears before
BLANK
(or REV) pin is deasserted. Q1 takes t
(~100μs)
Q1_ON
BLANK
time to turn on. Figure 6 depicts typical behavior in slow
reverse current conditions.
t
has elapsed. The switch turns off and stays off if
BLANK
the overcurrent condition continues beyond t
. To
A fast reverse-current condition is detected if (V - V
)
BLANK
IN
OUT
reset the switch, either toggle the control logic (EN) or
cycle the input voltage. Figure 5 depicts typical behavior
in latch-off current-limit mode.
< V
is present for reverse current blocking fast
RIBF
response time (t ). Only the input NFET (Q1) is turned
RIB
off and the FLAG (or REV) pin is asserted while the out-
put NFET (Q2) is kept on. During and after this time, the
device monitors the voltage difference between the OUT
and IN pins to determine whether the reverse current is
still present. Once the reverse current condition has been
removed, Q1 is turned back on and the FLAG (or REV)
pin is deasserted. Q1 takes t
turn on. Figure 7 depicts typical behavior in fast reverse-
current condition.
Reverse Current Protection
In MAX17612A and MAX17612C, the reverse current-
protection feature is enabled and it prevents reverse
current flow from OUT to IN pins. In MAX17612B, the
reverse current-protection feature is disabled, which
allows reverse current flow from the OUT to IN pins. This
feature is useful in applications with inductive loads.
(~100μs) time to
Q1_ON
In MAX17612A and MAX17612C devices, two differ-
ent reverse-current features are implemented. A slow
The device contains two reverse-current thresholds with
slow (< 140μs) and fast (< 150ns) response time for
reverse protection. The thresold values for slow reverse
is 11mV (typ) whereas for fast reverse, it is 105mV (typ).
This feature results in robust operation in a noisy environ-
ments, while still delivering fast protection for severe fault,
such as input short-circuit or hot plug-in at the OUT pins.
reverse-current condition is detected if (V - V
) <
OUT
IN
V
RIBS
is present for reverse current-blocking debounce
blanking time (t
). Only the input NFET (Q1) is
DEBRIB
turned off and the FLAG (or REV) pin is asserted while
the output NFET (Q2) is kept on. During and after this
LATCH-OFF MODE
tBLANK
tDEB
tBLANK
OUT
CURRENT LIMIT
LOAD CURRENT
DEVICE GOES TO
THERMAL SHUTDOWN
MODE AND LATCHES OFF
DEVICE LATCHES OFF
FLAG
INPUT OR EN CYCLE
(OR FWD)
TIME
NOTE: TIME NOT IN SCALE
Figure 5. Latch-Off Fault-Timing Diagram
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
tQ1_ON
tDEBRIB
tDEBRIP
(VIN-VOUT
)
0V
VRIBS
ILOAD
0A
-(VRIBS/RON
)
Q1 SWITCH
STATUS
FLAG
TIME
NOTE: TIME NOT IN SCALE
Figure 6. Slow Reverse-Current Fault-Timing Diagram
tQ1_ON
tDEBRIB
tRIB
(VIN-VOUT
)
0V
VRIBS
VRIBF
ILOAD
0A
-(VRIBS/RON
-(VRIBF/RON
)
)
Q1 SWITCH
STATUS
FLAG
TIME
NOTE: TIME NOT IN SCALE
Figure 7. Fast Reverse-Current Fault-Timing Diagram
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Fault Output
Applications Information
MAX17612A and MAX17612B devices have two open-
drain fault outputs, FLAG and UVOV. They require external
pullup resistors to a DC supply. The FLAG pin goes low
when any of the following conditions occur:
IN Capacitor
A 0.47μF capacitor from the IN pin to GND is recomended
to hold input voltage during sudden load-current changes.
Hot Plug-In at IN Terminal
● Overcurrent duration exceeds blanking time.
● Reverse current is detected (MAX17612A only).
● Thermal shutdown is active.
In many system powering applications, an input-filtering
capacitor is required to lower radiated emission and
enhance ESD capability. In hot plug-in applications,
parasitic cable inductance along with the input capacitor
causes overshoot and ringing when a live power cable is
connected to the input terminal.
● R
SETI is less than 1kΩ (max).
The other fault output UVOV goes low when input voltage
falls below UVLO threshold or rises above OVLO thresh-
old. Note that the UVLO fault has a debounce time of
16ms. This fault is removed 16ms after input voltage has
crossed the UVLO threshold. This debounce also elapses
only at powerup. As a consequence, the UVOV pin fault
signal is always asserted at power-up for at least 16ms.
This effect causes the protection device to see almost
twice the applied voltage. A transient voltage suppressor
(TVS) is often used in industrial applications to protect
the system from these conditions. A TVS that is capable
of limiting surge voltage to maximum 60V shall be placed
close to the input terminal for enhanced protection. The
maximum tolerated slew rate at the IN pins is 100V/μs.
The MAX17612C device has two open-drain fault outputs,
FWD and REV. They require external pullup resistors to
a DC supply. FWD goes low when any of the following
conditions occur:
● Overcurrent duration exceeds the blanking time.
● Thermal shutdown is active.
Input Hard Short to Ground
In many system applications, an input short-circuit pro-
tection is required. The MAX17612A and MAX17612C
devices detect reverse current entering at the OUT pin
and flowing out of the IN pin and turn off the internal FETs.
The magnitude of the reverse current depends on the
inductance of input circuitry and any capacitance installed
near the IN pins.
● R
is less than 1kΩ (max).
SETI
REV goes low when reverse current is detected.
Thermal Shutdown Protection
The devices can be damaged in case V goes so nega-
IN
The devices have a thermal shutdown feature to protect
against overheating. The devices turn off and the FLAG
(or FWD) pin asserts when the junction temperature
exceeds +160°C (typ). The devices exit thermal shutdown
and resume normal operation after the junction tempera-
ture cools down by 28°C (typ), except when in latchoff
mode, the devices remain latched off.
tive that (V
- V ) > 60V.
OUT
IN
OUT Capacitor
The maximum capacitive load (C ) that can be con-
MAX
nected is a function of current-limit setting (I
in mA),
LIM
the blanking time (t
in ms) and the input voltage.
BLANK
C
is calculated using the following relationship:
MAX
The thermal limit behaves similarly to the current limit. In
autoretry mode, the thermal limit works with the autoretry
timer. When the junction temperature falls below the fall-
ing thermal-shutdown threshold, devices turn on after the
retry time. In latch-off mode, the devices latch off until
power or EN is cycled. In continuous mode, the devices
only disable while the temperature is over the limit. There
is no blanking time for thermal protection. Figure 3,
Figure 4, and Figure 5 depict typical behavior under differ-
ent current limit modes.
I
(mA)× t
(ms)
BLANK(TYP)
LIM
C
(µF) =
MAX
V (V)
IN
For example, for V = 24V, t
= 40ms, and
IN
BLANK(TYP)
I
= 250mA, C
is 416μF.
LIM
MAX
Output capacitor values in excess of C
can trigger
MAX
false overcurrent conditions. Note that the above expres-
sion assumes no load current is drawn from the OUT pins.
Any load current drawn would offset the capacitor charg-
ing current resulting in a longer charging period; hence,
the possibility of a false overcurrent condition.
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Attention must be given to continuous current-limit mode
when the power dissipation during a fault condition can
cause the device to reach the thermal-shutdown threshold.
Thermal vias from the exposed pad to ground plane are
highly recommended to increase the system thermal capac-
itance while reducing the thermal resistance to the ambient.
Hot Plug-In at OUT Terminal
In some applications, there might be a possibility of apply-
ing an external voltage at the OUT terminal of the devices
with or without the presence of an input voltage. During
these conditions, devices detect any reverse current enter-
ing at the OUT pin and flowing out of the IN pin and turn
off the internal FETs. Parasitic cable inductance along
with input and output capacitors, cause overshoot and
ringing when an external voltage is applied at the OUT
terminal. This causes the protection devices to see up to
twice the applied voltage, which can damage the devices.
It is recommended to maintain overvoltages such that the
voltages at the pins do not exceed the absolute maximum
ratings. The maximum tolerated slew rate at OUT pins is
100V/μs.
ESD Protection
The devices are specified for ±15kV (HBM) ESD on IN
when IN is bypassed to ground with a 0.47μF, low-ESR
ceramic capacitor. No capacitor is required for ±2kV
(HBM) (typ) ESD on IN. All the pins have a ±2kV (HBM)
typical ESD protection. Figure 8 shows the HBM, and
Figure 9 shows the current waveform it generates when
discharged into low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the device through a 1.5kΩ
resistor.
Output Freewheeling Diode for Inductive
Hard Short to Ground
In applications that require protection from a sudden short
to ground with an inductive load or a long cable, a schottky
diode between the OUT terminal and gro und is recom-
mended. This is to prevent a negative spike on the OUT
due to the inductive kickback during a short-circuit event.
RC
1MΩ
RD
1.5kΩ
CHARGE-CURRENT- DISCHARGE
LIMIT RESISTOR RESISTOR
Layout and Thermal Dissipation
HIGH-
VOLTAGE
DC
To optimize the switch response time to output short-circuit
conditions, it is very important to keep all traces as short
as possible to reduce the effect of undesirable parasitic
inductance. Place input and output capacitors as close as
possible to the device (no more than 5mm). IN and OUT
must be connected with wide short traces to the power
bus. During normal operation, the power dissipation is
small and the package temperature change is minimal.
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
SOURCE
Figure 8. Human Body ESD Test Model
Power dissipation under steady-state normal operation is
calculated as:
2
OUT
P
= I
×R
(SS)
ON
IP 100%
90%
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
IR
Refer to the Electrical Characteristics table and Typical
Operating Characteristics for R
ating temperatures.
values at various oper-
AMPERES
36.8%
ON
If the output is continuously shorted to ground at the
maximum supply voltage, the switches with the autoretry
option do not cause thermal shutdown detection to trip.
Power dissipation in the devices operating in autoretry
mode is calculated using the following equation:
10%
0
0
TIME
tDL
CURRENT WAVEFORM
tRL
Figure 9. Human Body Current Waveform
V
×I
× t
IN(MAX) OUT(MAX) BLANK
P
=
(MAX)
t
+ t
BLANK
RETRY
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Ordering Information
PART
TEMP RANGE
PIN PACKAGE
10 TDFN-EP*
10 TDFN-EP*
10 TDFN-EP*
FEATURE DIFFERENCES
OV, UV, Reverse Voltage Protection
OV, UV
MAX17612AATB+T
MAX17612BATB+T
MAX17612CATB+T
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
Reverse Voltage Protection
+Denotes a lead(Pb)-free/RoHS-compliant package.
T Denotes tape-and-reel.
*EP = Exposed Pad
Maxim Integrated
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MAX17612A/MAX17612B/
MAX17612C
4.5V to 60V, 250mA Current-Limiter with
OV, UV, and Reverse Protection
Revision History
REVISION REVISION
PAGES
DESCRIPTION
CHANGED
NUMBER
DATE
0
6/18
Initial release
—
1
.1
Corrected typo
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.
Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses
are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits)
shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.
©
Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc.
2018 Maxim Integrated Products, Inc.
│ 21
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