MAX17502
60V, 1A, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
General Description
The MAX17502 high-efficiency, high-voltage, synchronous
step-down DC-DC converter with integrated MOSFETs
operates over a 4.5V to 60V input voltage range. This
device is offered in a fixed 3.3V , 5V or adjustable output
voltage (0.9V to 92%V
IN
) while delivering up to 1A of
current. The output voltage is accurate to within ±1.7%
over -40°C to +125°C. The MAX17502 is available in
compact TDFN and TSSOP packages. Simulation models
are available.
The device features peak-current-mode control with
pulse-width modulation (PWM) and operates with fixed
switching frequency at any load. The low-resistance,
on-chip MOSFETs ensure high efficiency at full load and
simplify the layout.
A programmable soft-start feature allows users to reduce
input inrush current. The device also incorporates an
output enable/undervoltage lockout pin (EN/UVLO) that
allows the user to turn on the part at the desired input-
voltage level. An open-drain
RESET
pin provides a
delayed power-good signal to the system upon achieving
successful regulation of the output voltage.
Benefits and Features
● Eliminates External Components and Reduces Total
Cost
•
No Schottky-Synchronous Operation for High
Efficiency and Reduced Cost
• Internal Compensation and Feedback Divider for
3.3V and 5V Fixed Outputs
• All-Ceramic Capacitors, Ultra-Compact Layout
● Reduces Number of DC-DC Regulators to Stock
•
Wide 4.5V to 60V Input Voltage Range
• 0.9V to 92%V
IN
Adjustable Output Voltage
• Delivers up to 1A
•
600kHz and 300kHz Switching Frequency Options
• Available in a 10-Pin, 3mm x 2mm TDFN and
14-Pin, 5mm x 4.4mm TSSOP Packages
● Reduces Power Dissipation
• Peak Efficiency > 90%
•
Shutdown Current = 0.9μA (typ)
● Operates Reliably in Adverse Industrial Environments
•
Hiccup-Mode Current Limit, Sink Current Limit,
and Autoretry Startup
•
Built-In Output-Voltage Monitoring (Open-Drain
RESET
Pin)
•
Resistor-Programmable EN/UVLO Threshold
• Adjustable Soft-Start and Prebiased Power-Up
• High Industrial -40°C to +125°C Ambient Operating
Temperature Range/-40°C to +150°C Junction
Temperature Range
Ordering Information/Selector Guide
appears at end of data
sheet.
Applications
●
●
●
●
●
●
Industrial Process Control
HVAC and Building Control
Base Station, VOIP, Telecom
Home Theatre
Battery-Powered Equipment
General-Purpose Point-of-Load
19-6245 Rev 5; 6/16
MAX17502
60V, 1A, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Absolute Maximum Ratings
V
IN
to GND.............................................................-0.3V to +70V
EN/UVLO to GND.......................................-0.3V
to (V
IN
+ 0.3V)
LX to PGND................................................-0.3V
to (V
IN
+ 0.3V)
FB, RESET, COMP, SS to GND
.............................-0.3V to +6V
V
CC
to GND..............................................................-0.3V to +6V
GND to PGND.......................................................-0.3V to +0.3V
LX Total RMS Current......................................................... ±1.6A
Output Short-Circuit Duration.....................................Continuous
Junction Temperature......................................................+150°C
Storage Temperature Range............................. -65°C to +160°C
Lead Temperature (soldering, 10s).................................+300°C
Soldering Temperature (reflow).......................................+260°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. Junction temperature greater than +125°C degrades operating lifetimes.
Package Thermal Characteristics
(Note 1)
10 TDFN
14 TSSOP
Continuous Power Dissipation (T
A
= +70°C)
Continuous Power Dissipation (T
A
= +70°C)
(derate 14.9mW/°C above +70°C) (multilayer board) .1188.7mW
(derate 25.6mw/°C above +70°C) ..........................2051.3mW
Junction-to-Ambient Thermal Resistance (θ
JA
) ...........67.3°C/W
Junction-to-Ambient Thermal Resistance (θ
JA
) ..............39°C/W
Junction-to-Case Thermal Resistance (θ
JC
) ................18.2°C/W
Junction-to-Case Thermal Resistance (θ
JC
) .....................3°C/W
Note 1:
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
IN
= 24V, V
GND
= V
PGND
= 0V, C
VIN
= 2.2μF, C
VCC
= 1μF, V
EN
= 1.5V, C
SS
= 3300pF, V
FB
= 0.98 x V
OUT
, LX = unconnected,
RESET
= unconnected. T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. All voltages are referenced
to GND, unless otherwise noted.) (Note 2)
PARAMETER
INPUT SUPPLY (V
IN
)
Input Voltage Range
V
IN
I
IN-SH
Input Supply Current
I
IN-SW
V
EN
= 0V, shutdown mode
Normal
MAX17502E/F/G
switching mode,
MAX17502H
no load
V
EN
rising
V
EN
falling
V
EN
falling, true shutdown
V
EN
= V
IN
= 60V, T
A
= +25°C
6V < V
IN
< 12V, 0mA < I
VCC
< 10mA,
12V < V
IN
< 60V, 0mA < I
VCC
< 2mA
V
CC
= 4.3V, V
IN
= 12V
V
IN
= 4.5V, I
VCC
= 5mA
V
CC
rising
V
CC
falling
1.194
1.114
4.5
0.9
4.75
2.5
1.218
1.135
0.7
8
200
nA
60
3.5
6.75
3.6
1.236
1.156
V
V
µA
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ENABLE/UVLO (EN/UVLO)
V
ENR
EN Threshold
EN Input Leakage Current
LDO
V
CC
Output Voltage Range
V
CC
Current Limit
V
CC
Dropout
V
CC
UVLO
V
CC
I
VCC-MAX
V
CC-DO
V
CC-UVR
V
CC-UVF
4.65
15
4.1
3.85
3.55
4
3.7
4.15
3.85
5
40
5.35
80
V
mA
V
V
V
ENF
V
EN-TRUESD
I
EN
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Maxim Integrated
│
2
MAX17502
60V, 1A, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Electrical Characteristics (continued)
(V
IN
= 24V, V
GND
= V
PGND
= 0V, C
VIN
= 2.2μF, C
VCC
= 1μF, V
EN
= 1.5V, C
SS
= 3300pF, V
FB
= 0.98 x V
OUT
, LX = unconnected,
RESET
= unconnected. T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. All voltages are referenced
to GND, unless otherwise noted.) (Note 2)
PARAMETER
POWER MOSFETs
High-Side pMOS On-Resistance
R
DS-ONH
I
LX
= 0.5A
(sourcing)
I
LX
= 0.5A
(sinking)
T
A
= +25°C
T
A
= T
J
= +125°C
(Note 3)
T
A
= +25°C
T
A
= T
J
= +125°C
(Note 3)
0.2
0.55
0.85
1.2
0.35
0.47
1
Ω
Ω
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Low-Side nMOS On-Resistance
R
DS-ONL
LX Leakage Current
SOFT-START (SS)
Charging Current
FEEDBACK (FB/VO)
FB Regulation Voltage
I
LX_LKG
V
EN
= 0V, T
A
= +25°C,
V
LX
= (V
PGND
+ 1V) to (V
IN
- 1V)
V
SS
= 0.5V
MAX17501G/H
MAX17502E, V
FB
=
3.3V
4.7
0.884
6.8
6.8
5
0.9
12
12
µA
I
SS
V
FB_REG
5.3
0.916
17
µA
V
FB Input Bias Current
I
FB
T
A
= +25NC
MAX17502F, V
FB
= 5V
MAX17502G/H, V
FB
= 0.9V
µA
17
100
nA
OUTPUT VOLTAGE (V
OUT
)
MAX17502E
MAX17502F
Output Voltage Range
V
OUT
MAX17502G
MAX17502H
TRANSCONDUCTANCE AMPLIFIER (COMP)
Transconductance
COMP Source Current
COMP Sink Current
Current-Sense Transresistance
G
M
I
COMP_SRC
I
COMP_SINK
R
CS
I
COMP
= ±2.5µA, MAX17502G/H
MAX17502G/H
MAX17502G/H
MAX17502G/H
510
19
19
0.45
590
32
32
0.5
650
55
55
0.55
µS
µA
µA
V/A
3.248
4.922
0.9
0.9
3.3
5
3.352
5.08
0.92 x
V
IN
0.965
x V
IN
V
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Maxim Integrated
│
3
MAX17502
60V, 1A, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Electrical Characteristics (continued)
(V
IN
= 24V, V
GND
= V
PGND
= 0V, C
VIN
= 2.2μF, C
VCC
= 1μF, V
EN
= 1.5V, C
SS
= 3300pF, V
FB
= 0.98 x V
OUT
, LX = unconnected,
RESET
= unconnected. T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. All voltages are referenced
to GND, unless otherwise noted.) (Note 2)
PARAMETER
CURRENT LIMIT
Peak Current-Limit Threshold
Runaway Current-Limit Threshold
Sink Current-Limit Threshold
TIMINGS
Switching Frequency
Events to Hiccup after Crossing
Runaway Current Limit
V
OUT
Undervoltage Trip Level to
Cause Hiccup
HICCUP Timeout
Minimum On-Time
Maximum Duty Cycle
LX Dead Time
RESET
RESET
Output Level Low
RESET
Output Leakage
Current High
V
OUT
Threshold for
RESET
Falling
V
OUT
Threshold for
RESET Rising
RESET Delay After FB Reaches
95% Regulation
THERMAL SHUTDOWN
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
Temperature rising
165
10
°C
°C
V
OUT-OKF
V
OUT-OKR
I
RESET
= 1mA
V
FB
= 1.01 x V
FB-REG
, T
A
= +25°C
V
FB
falling
V
FB
rising
V
FB
rising
90.5
93.5
92.5
95.5
1024
0.02
0.45
94.5
97.5
V
µA
%
%
Cycles
t
ON_MIN
D
MAX
V
FB
= 0.98 x
MAX17502E/F/G
V
FB-REG
MAX17502H
92
96.5
V
OUT-HICF
V
SS
> 0.95V (soft-start is done)
69.14
f
SW
V
FB
> V
OUT-
MAX17502E/F/G
MAX17502H
HICF
V
FB
< V
OUT-HICF
560
280
280
600
300
300
1
71.14
32,768
75
94
97.5
5
120
96
98.5
73.14
640
320
320
Event
%
Cycles
ns
%
ns
kHz
I
PEAK-LIMIT
I
RUNAWAY-
LIMIT
SYMBOL
CONDITIONS
MIN
1.4
1.45
TYP
1.65
1.7
0.65
MAX
1.9
2
0.74
UNITS
A
A
A
I
SINK-LIMIT
MAX17502E/F/G/H
0.56
Note 2:
All limits are 100% tested at +25°C. Limits over the operating temperature range and relevant supply voltage range are
guaranteed by design and characterization.
Note 3:
Guaranteed by design, not production tested.
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Maxim Integrated
│
4
MAX17502
60V, 1A, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics
(V
IN
= 24V, V
GND
= V
PGND
= 0V, C
VIN
= 2.2μF, C
VCC
= 1μF, V
EN
= 1.5V, C
SS
= 3300pF, V
FB
= 0.98 x V
OUT
, LX = unconnected,
RESET
= unconnected, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. All voltages are referenced
to GND, unless otherwise noted.)
MAX17502E
EFFICIENCY vs. LOAD CURRENT,
3.3V OUTPUT, FIGURE 7 CIRCUIT
MAX17502 toc01
MAX17502 toc02
OUTPUT VOLTAGE (V)
90
EFFICIENCY (%)
90
EFFICIENCY (%)
80
70
60
3.305
3.300
3.295
3.290
3.285
3.280
80
V
IN
= 24V
V
IN
= 12V
V
IN
= 36V
V
IN
= 12V
V
IN
= 24V
V
IN
= 36V
V
IN
= 48V
70
V
IN
= 12V
V
IN
= 24V
V
IN
= 36V
60
100 200 300 400 500 600 700 800 900 1000
LOAD CURRENT (mA)
50
100 200 300 400 500 600 700 800 900 1000
LOAD CURRENT (mA)
0 100 200 300 400 500 600 700 800 900 1000
LOAD CURRENT (mA)
MAX17502 toc04
MAX17502 toc05
5.04
5.03
OUTPUT VOLTAGE (V)
5.02
5.01
5.00
4.99
4.98
4.97
4.96
4.95
1.05
SHUTDOWN CURRENT (µA)
1.00
0.95
0.90
0.85
0.80
0.75
0.70
-40 -20
0
20
40
60
80
NO-LOAD SWITCHING CURRENT (mA)
4.95
4.90
V
IN
= 12V
V
IN
= 24V
V
IN
= 36V
V
IN
= 48V
4.85
0 100 200 300 400 500 600 700 800 900 1000
LOAD CURRENT (mA)
100 120
4.80
-40 -20
0
20
40
60
80
100 120
TEMPERATURE (°C)
TEMPERATURE (°C)
MAX17502 toc07
EN/UVLO THRESHOLD VOLTAGE (V)
1.22
1.21
1.20
1.19
1.18
1.17
1.16
1.15
1.14
1.13
1.12
-40 -20
0
20
40
60
80
MAX17502 toc08
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
RISING
THRESHOLD
3.325
5.025
3.300
5.000
FALLING
THRESHOLD
3.275
4.975
100 120
3.250
TEMPERATURE (°C)
-40 -20
0
20
40
60
80
100 120
4.950
-40 -20
0
20
40
60
80
100 120
TEMPERATURE (°C)
TEMPERATURE (°C)
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Maxim Integrated
│
5
MAX17502 toc09
1.23
EN/UVLO THRESHOLD
vs. TEMPERATURE
3.350
OUTPUT VOLTAGE
vs. TEMPERATURE (MAX17502E),
3.3V OUTPUT, FIGURE 7 CIRCUIT
5.050
OUTPUT VOLTAGE
vs. TEMPERATURE (MAX17502F),
5V OUTPUT, FIGURE 8 CIRCUIT
MAX17502 toc06
5.05
MAX17502F
LOAD AND LINE REGULATION,
5V OUTPUT, FIGURE 8 CIRCUIT
1.10
SHUTDOWN CURRENT
vs. TEMPERATURE
5.00
NO-LOAD SWITCHING CURRENT
vs. TEMPERATURE
MAX17502 toc03
100
100
MAX17502F
EFFICIENCY vs. LOAD CURRENT,
5V OUTPUT, FIGURE 8 CIRCUIT
3.310
MAX17502E
LOAD AND LINE REGULATION,
3.3V OUTPUT, FIGURE 7 CIRCUIT
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