MAX17501HATB+T [MAXIM]
Switching Regulator;
| 型号： | MAX17501HATB+T |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Switching Regulator 开关 |
| 文件： | 总22页 (文件大小：1424K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
EVALUATION KIT AVAILABLE
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
General Description
Benefits and Features
● Eliminates External Components and Reduce Total Cost
•ꢀ No Schottky-Synchronous Operation for High
EfficiencyꢀandꢀReducedꢀCost
The MAX17501 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
•ꢀ Internal Compensation and Feedback Divider for
3.3V and 5V Fixed Outputs
voltage (0.9V to 92%V ) while delivering up to 500mA
IN
of current. The output voltage is accurate to within
±1.7% over -40°C to +125°C. The MAX17501 is available
in a compact TDFN package. Simulation models are
available.
•ꢀ 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 Adjustable Output Voltage
IN
•ꢀ Delivers Up to 500mA
The device features peak-current-mode control with
pulse-width modulation (PWM). Users can choose devices
with either pulse frequency modulation (PFM) or forced
PWM scheme. PFM devices skip pulses at light load
for higher efficiency, while forced-PWM devices operate
with fixed switching frequency at any load for noise sensitive-
applications. The low-resistance, on-chip MOSFETs
ensure high efficiency at full load and simplify the layout.
•ꢀ 600kHz and 300kHz Switching Frequency Options
•ꢀ Available in a 10-Pin, 3mm x 2mm TDFN Package
● Reduces Power Dissipation
•ꢀ PeakꢀEfficiencyꢀ>ꢀ90%
•ꢀ PFMꢀFeatureꢀforꢀHighꢀLight-LoadꢀEfficiency
•ꢀ ShutdownꢀCurrentꢀ=ꢀ0.9μAꢀ(typ)
● Operates Reliably in Adverse Industrial Environments
•ꢀ Hiccup-Mode Current Limit, Sink Current Limit, and
Autoretry Startup
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.
•ꢀ 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
Applications
● Industrial Process Control
● HVAC and Building Control
● Base Station, VOIP, Telecom
● Home Theatre
Ordering Information/Selector Guide appears at end of data sheet.
● Battery-Powered Equipment
● General-Purpose Point-of-Load
19-6244; Rev 7; 7/16
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Absolute Maximum Ratings
IN
V
to GND.............................................................-0.3V to +70V
Continuous Power Dissipation (T = +70°C)
A
EN/UVLO to GND.......................................-0.3V to (V + 0.3V)
(derate 14.9mW/°C above +70°C) (multilayer board).1188.7mW
Junction Temperature......................................................+150°C
Storage Temperature Range............................. -65°C to +160°C
Lead Temperature (soldering, 10s).................................+300°C
Soldering Temperature (reflow).......................................+260°C
IN
LX to PGND................................................-0.3V to (V + 0.3V)
IN
FB, RESET, COMP, SS to GND .............................-0.3V to +6V
V
to GND..............................................................-0.3V to +6V
CC
GND to PGND.......................................................-0.3V to +0.3V
LX Total RMS Current......................................................... ±1.6A
Output Short-Circuit Duration.....................................Continuous
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.
(Note 1)
Package Thermal Characteristics
TDFN
Junction-to-AmbientꢀThermalꢀResistanceꢀ(θ ) .......67.3°C/W
JA
Junction-to-CaseꢀThermalꢀResistanceꢀ(θ )............18.2°C/W
JC
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 = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected. T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
INPUT SUPPLY (V
)
IN
Input Voltage Range
V
4.5
60
3.5
145
V
IN
IN-SH
IN-HIBERNATE
I
V
V
= 0V, shutdown mode
0.9
90
EN
µA
I
= 1.03 x V
, MAX17501A/B
FB
OUT
Input Supply Current
MAX17501E/F/G
MAX17501H
4.75
2.5
6.75
3.6
Normal switching
mode, no load
I
mA
IN-SW
ENABLE/UVLO (EN/UVLO)
V
V
V
V
V
rising
falling
1.194
1.114
1.218
1.135
0.7
1.236
1.156
ENR
EN
EN
EN
EN
EN Threshold
V
V
ENF
EN-TRUESD
V
falling, true shutdown
= V = 60V, T = +25°C
EN Input Leakage Current
I
8
200
nA
EN
IN
A
LDO
6V < V < 12V, 0mA < I
< 10mA,
IN
VCC
V
Output Voltage Range
V
4.65
5
5.35
80
V
CC
CC
12V < V < 60V, 0mA < I
< 2mA
IN
VCC
V
V
Current Limit
Dropout
I
V
V
V
V
= 4.3V, V = 12V
15
40
mA
V
CC
VCC-MAX
CC
IN
V
= 4.5V, I = 5mA
VCC
4.1
CC
CC-DO
IN
V
rising
falling
3.85
3.55
4
4.15
3.85
CC-UVR
CC
CC
V
UVLO
V
CC
V
3.7
CC-UVF
Maxim Integrated
│ 2
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Electrical Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected. T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER MOSFETs
T
T
= +25°C
0.55
0.85
1.2
A
A
I
= 0.5A
LX
High-Side pMOS On-Resistance
R
Ω
= T = +125°C
DS-ONH
J
(sourcing)
(Note 3)
T
= +25°C
0.2
0.35
0.47
A
A
I
= 0.5A
LX
Low-Side nMOS On-Resistance
LX Leakage Current
R
Ω
T
= T = +125°C
J
DS-ONL
(sinking)
(Note 3)
V
V
= 0V, T = +25°C,
EN
LX
A
I
1
µA
LX_LKG
= (V
+ 1V) to (V - 1V)
IN
PGND
SOFT-START (SS)
Charging Current
I
V
= 0.5V
4.7
5
5.3
µA
V
SS
SS
FEEDBACK (FB/VO)
FB Regulation Voltage
V
MAX17501G/H
0.884
6.8
0.9
12
0.916
17
FB_REG
MAX17501A/E,
V
= 3.3V
FB
µA
nA
MAX17501B/F,
= 5V
FB Input Bias Current
I
T
= +25NC
6.8
12
17
FB
A
V
FB
MAX17501G/H,
= 0.9V
100
V
FB
OUTPUT VOLTAGE (V
)
OUT
MAX17501A
3.248
3.380
3.448
MAX17501B
MAX17501E
MAX17501F
4.922
3.248
4.922
5.121
3.3
5
5.225
3.352
5.08
Output Voltage Accuracy
V
OUT
V
TRANSCONDUCTANCE AMPLIFIER (COMP)
Transconductance
G
I
= ±2.5µA, MAX17501G/H
COMP
510
19
590
32
32
1
650
55
µS
µA
M
COMP Source Current
COMP Sink Current
I
MAX17501G/H
MAX17501G/H
MAX17501G/H
COMP_SRC
I
19
55
µA
COMP_SINK
Current-Sense Transresistance
CURRENT LIMIT
R
0.9
1.1
V/A
CS
Peak Current-Limit Threshold
I
0.64
0.65
0.76
0.78
0.86
A
A
PEAK-LIMIT
I
RUNAWAY-
LIMIT
Runaway Current-Limit Threshold
0.905
MAX17501A/B
0.03
0.35
Sink Current-Limit Threshold
PFM Current-Limit Threshold
I
A
A
SINK-LIMIT
MAX17501E/F/G/H
MAX17501A/B
0.3
0.4
I
0.125
PFM
Maxim Integrated
│ 3
www.maximintegrated.com
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Electrical Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected. T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.) (Note 2)
PARAMETER
TIMINGS
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX17501A/B/E/F/G
MAX17501H
560
280
280
600
300
300
640
320
320
V
ꢀ>ꢀV
FB
HICF
OUT-
Switching Frequency
f
kHz
SW
V
< V
OUT-HICF
FB
Events to Hiccup after Crossing
Runaway Current Limit
1
Event
%
V
Undervoltage Trip Level to
OUT
V
V
>ꢀ0.95Vꢀ(soft-startꢀisꢀdone)
69.14
71.14
73.14
OUT-HICF
SS
Cause Hiccup
HICCUP Timeout
Minimum On-Time
32,768
75
Cycles
ns
t
120
96
ON_MIN
MAX17501A/B/E/F/G
MAX17501H
92
94
V
V
= 0.98 x
FB
Maximum Duty Cycle
D
%
MAX
96.5
97.5
5
98.5
FB-REG
LX Dead Time
RESET
ns
0.02
0.45
V
I
= 1mA
RESET Output Level Low
RESET
RESET Output Leakage
Current High
V
= 1.01 x V
, T = +25°C
µA
FB
FB-REG
A
V
V
V
V
falling
rising
90.5
93.5
92.5
95.5
94.5
97.5
%
%
V
V
Threshold for RESET Falling
OUT-OKF
FB
OUT
Threshold for RESET Rising
OUT-OKR
FB
OUT
RESET Delay After FB Reaches
95% Regulation
V
rising
1024
Cycles
FB
THERMAL SHUTDOWN
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
Temperature rising
165
10
°C
°C
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.
Maxim Integrated
│ 4
www.maximintegrated.com
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
(MAX17501B), 5V OUTPUT, FIGURE 7 CIRCUIT
100
EFFICIENCY vs. LOAD CURRENT
EFFICIENCY vs. LOAD CURRENT
(MAX17501A), 3.3V OUTPUT, FIGURE 6 CIRCUIT
100
(MAX17501E), 3.3V OUTPUT, FIGURE 6 CIRCUIT
95
90
85
80
75
90
80
70
60
50
40
30
90
80
70
60
50
40
30
V
= 24V
= 36V
IN
IN
V
IN
= 12V
V
= 24V
V = 36V
IN
IN
70
65
60
55
50
45
V
IN
= 12V
V
= 36V
IN
V
V
= 24V
IN
V
IN
= 48V
100
V
IN
= 12V
10
1
100
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
1
10
LOAD CURRENT (mA)
LOAD CURRENT (mA)
OUTPUT VOLTAGE vs. LOAD CURRENT
(MAX17501A), 3.3V OUTPUT, FIGURE 6 CIRCUIT
3.45
OUTPUT VOLTAGE vs. LOAD CURRENT
EFFICIENCY vs. LOAD CURRENT
(MAX17501F), 5V OUTPUT, FIGURE 7 CIRCUIT
(MAX17501B), 5V OUTPUT, FIGURE 7 CIRCUIT
5.20
100
90
80
70
60
50
40
V
= 12V
IN
5.15
5.10
5.05
5.00
4.95
4.90
V
= 12V
= 24V
= 36V
= 48V
IN
3.40
3.35
3.30
3.25
V
V
V
IN
IN
IN
V
= 36V
IN
V
IN
= 36V
V = 48V
IN
V
= 24V
IN
V
IN
= 24V
V
= 12V
IN
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
OUTPUT VOLTAGE vs. LOAD CURRENT
OUTPUT VOLTAGE vs. LOAD CURRENT
(MAX17501F), 5V OUTPUT, FIGURE 7 CIRCUIT
SHUTDOWN CURRENT
vs. TEMPERATURE
(MAX17501E), 3.3V OUTPUT, FIGURE 6 CIRCUIT
3.320
5.05
1.10
1.05
1.00
0.95
0.90
0.85
0.80
0.75
0.70
5.04
5.03
5.02
5.01
5.00
4.99
4.98
4.97
4.96
4.95
3.315
3.310
3.305
3.300
3.295
3.290
V
IN
= 48V V = 36V V = 24V V = 12V
IN IN IN
V
IN
= 36V
V
IN
= 24V
V
IN
= 12V
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
0
50 100 150 200 250 300 350 400 450 500
LOAD CURRENT (mA)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
Maxim Integrated
│ 5
www.maximintegrated.com
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
NO-LOAD SWITCHING CURRENT
vs. TEMPERATURE (PFM OPERATION)
NO-LOAD SWITCHING CURRENT vs. TEMPERATURE
EN/UVLO THRESHOLD
vs. TEMPERATURE
(FORCED-PWM OPERATION)
140
120
100
80
5.00
1.23
1.22
1.21
1.20
1.19
1.18
1.17
1.16
1.15
1.14
1.13
1.12
4.95
4.90
4.85
4.80
RISING
THRESHOLD
FALLING
THRESHOLD
60
40
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
NO-LOAD OUTPUT VOLTAGE
FEEDBACK VOLTAGE
vs. TEMPERATURE
NO-LOAD OUTPUT VOLTAGE
vs. TEMPERATURE (MAX17501F),
5V OUTPUT, FIGURE 7 CIRCUIT
vs. TEMPERATURE (MAX17501E),
3.3V OUTPUT, FIGURE 6 CIRCUIT
0.92
0.91
0.90
0.89
0.88
5.050
5.025
5.000
4.975
4.950
3.350
3.325
3.300
3.275
3.250
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
PEAK AND RUNAWAY CURRENT LIMIT
vs. TEMPERATURE
SWITCHING FREQUENCY
vs. TEMPERATURE
NO-LOAD SOFT-START FROM EN/UVLO
(MAX17501A), 3.3V OUTPUT, FIGURE 6 CIRCUIT
MAX17501 toc18
0.90
0.85
0.80
0.75
0.70
0.65
0.60
700
600
500
400
300
200
EN/UVLO
2V/div
RUNAWAY
CURRENT
LIMIT
V
PEAK
CURRENT
LIMIT
OUT
1V/div
RESET
2V/div
1ms/div
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
-40 -20
0
20 40 60 80 100 120
TEMPERATURE (°C)
Maxim Integrated
│ 6
www.maximintegrated.com
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
NO-LOAD SOFT-START FROM EN/UVLO
(MAX17501B), 5V OUTPUT, FIGURE 7 CIRCUIT
FULL-LOAD SOFT-START/SHUTDOWN FROM EN/UVLO
(MAX17501E), 3.3V OUTPUT, FIGURE 6 CIRCUIT
MAX17501 toc19
MAX17501 toc20
EN/UVLO
2V/div
EN/UVLO
2V/div
V
V
OUT
OUT
1V/div
2V/div
I
OUT
200mA/div
RESET
5V/div
RESET
2V/div
1ms/div
1ms/div
NO-LOAD SOFT-START FROM V
FULL-LOAD SOFT-START/SHUTDOWN FROM EN/UVLO
IN
(MAX17501A), 3.3V OUTPUT, FIGURE 6 CIRCUIT
(MAX17501F), 5V OUTPUT, FIGURE 7 CIRCUIT
MAX17501 toc22
MAX17501 toc21
V
IN
20V/div
EN/UVLO
2V/div
V
OUT
2V/div
I
OUT
200mA/div
V
OUT
1V/div
RESET
2V/div
RESET
5V/div
400µs/div
1ms/div
NO-LOAD SOFT-START FROM V
FULL-LOAD SOFT-START FROM V
IN
IN
(MAX17501B), 5V OUTPUT, FIGURE 7 CIRCUIT
(MAX17501E), 3.3V OUTPUT, FIGURE 6 CIRCUIT
MAX17501 toc23
MAX17501 toc24
V
V
IN
IN
20V/div
20V/div
I
OUT
200mA/div
V
OUT
2V/div
V
OUT
1V/div
RESET
2V/div
RESET
5V/div
400µs/div
400µs/div
Maxim Integrated
│ 7
www.maximintegrated.com
MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
FULL-LOAD SOFT-START FROM V
IN
SOFT-START WITH 2V PREBIAS
(MAX17501A), 3.3V OUTPUT, FIGURE 6 CIRCUIT
(MAX17501F), 5V OUTPUT, FIGURE 7 CIRCUIT
MAX17501 toc26
MAX17501 toc25
V
EN/UVLO
2V/div
IN
20V/div
V
OUT
1V/div
I
OUT
200mA/div
V
OUT
2V/div
RESET
5V/div
RESET
2V/div
400µs/div
400µs/div
SOFT-START WITH 2.5V PREBIAS
SOFT-START WITH 2V PREBIAS
(MAX17501B), 5V OUTPUT, FIGURE 7 CIRCUIT
MAX17501 toc27
(MAX17501E), 3.3V OUTPUT, FIGURE 6 CIRCUIT
MAX17501 toc28
EN/UVLO
2V/div
EN/UVLO
2V/div
V
OUT
1V/div
V
OUT
1V/div
RESET
5V/div
RESET
2V/div
400µs/div
400µs/div
LOAD TRANSIENT RESPONSE OF MAX17501A
SOFT-START WITH 2.5V PREBIAS
(LOAD CURRENT STEPPED FROM 5mA TO 255mA),
(MAX17501F), 5V OUTPUT, FIGURE 7 CIRCUIT
MAX17501 toc29
3.3V OUTPUT, FIGURE 6 CIRCUIT
MAX17501 toc30
V
(AC)
OUT
100mV/div
EN/UVLO
2V/div
V
OUT
1V/div
RESET
5V/div
I
OUT
100mA/div
400µs/div
200µs/div
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
LOAD TRANSIENT RESPONSE OF MAX17501B
LOAD TRANSIENT RESPONSE OF MAX17501E
(LOAD CURRENT STEPPED FROM NO-LOAD TO 250mA),
3.3V OUTPUT, FIGURE 6 CIRCUIT
(LOAD CURRENT STEPPED FROM 5mA TO 255mA),
5V OUTPUT, FIGURE 7 CIRCUIT
V
(AC)
OUT
100mV/div
V (AC)
OUT
50mV/div
I
OUT
100mA/div
I
OUT
100mA/div
200µs/div
20µs/div
LOAD TRANSIENT RESPONSE OF MAX17501F
(LOAD CURRENT STEPPED FROM NO-LOAD TO 250mA),
5V OUTPUT, FIGURE 7 CIRCUIT
LOAD TRANSIENT RESPONSE OF MAX17501E
(LOAD CURRENT STEPPED FROM 250mA TO 500mA),
3.3V OUTPUT, FIGURE 6 CIRCUIT
V
(AC)
V (AC)
OUT
50mV/div
OUT
100mV/div
I
OUT
200mA/div
I
OUT
100mA/div
20µs/div
20µs/div
LOAD TRANSIENT RESPONSE OF MAX17501F
(LOAD CURRENT STEPPED FROM 250mA TO 500mA),
5V OUTPUT, FIGURE 7 CIRCUIT
SWITCHING WAVEFORMS OF MAX17501F
AT 500mA LOAD, 5V OUTPUT, FIGURE 7 CIRCUIT
V
(AC)
OUT
50mV/div
V
(AC)
OUT
100mV/div
I
LX
500mA/div
I
OUT
200mA/div
LX
10V/div
20µs/div
2µs/div
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Operating Characteristics (continued)
(V = 24V, V
= V
= 0V, C
= C
ꢀ=ꢀ1μF,ꢀV
= 1.5V, C = 3300pF, V = 0.98 x V
, LX = unconnected, RESET =
OUT
IN
GND
PGND
VIN
VCC
EN
SS
FB
unconnected, T = -40°C to +125°C, unless otherwise noted. Typical values are at T = +25°C. All voltages are referenced to GND,
A
A
unless otherwise noted.)
SWITCHING WAVEFORMS OF MAX17501A
AT 15mA LOAD, 3.3V OUTPUT, FIGURE 6 CIRCUIT
OUTPUT OVERLOAD PROTECTION
OF MAX17501F, 5V OUTPUT, FIGURE 7 CIRCUIT
V
(AC)
OUT
100mV/div
V
OUT
2V/div
LX
10V/div
I
OUT
200mA/div
I
LX
100mA/div
20ms/div
10µs/div
BODE PLOT OF MAX17501F
AT 500mA LOAD, 5V OUTPUT, FIGURE 7 CIRCUIT
BODE PLOT OF MAX17501E
AT 500mA LOAD, 3.3V OUTPUT, FIGURE 6 CIRCUIT
f
= 51kHz
CR
PM = 55°
f
= 49.8kHz
CR
PM = 62°
4
5
6
7
8 9 1
2
4
5
6
7 8 9 1
2
MAX17501, 5V OUTPUT, 0.5A LOAD CURRENT,
FIGURE 7 CIRCUIT, CONDUCTED EMI CURVE
70
QUASI-PEAK LIMIT
AVERAGE LIMIT
60
50
40
30
20
10
PEAK
EMISSIONS
AVERAGE
EMISSIONS
30
1
10
0.15
FREQUENCY (MHz)
Measured on the MAX17501FTEVKIT with input filter—
C
IN
= 2.2µF, L = 4.7µH, 2.2µF additional input capaci-
IN
tor used.
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Pin Configuration
TOP VIEW
MAX17501
PGND
1
2
10 LX
+
V
IN
9
GND
EN/UVLO
3
4
5
8
7
6
RESET
N.C./COMP
SS
V
CC
EP*
FB/VO
TDFN
(3mm x 2mm)
*EP = EXPOSED PAD. CONNECT TO GND
Pin Description
PIN
NAME
FUNCTION
Power Ground. Connect PGND externally to the power ground plane. Connect GND and PGND pins
1
PGND
together at the ground return path of the V
bypass capacitor.
CC
2
V
IN
Power-Supply Input. The input supply range is from 4.5V to 60V.
Enable/Undervoltage Lockout Input. Drive EN/UVLO high to enable the output voltage. Connect to the
3
EN/UVLO
center of the resistive divider between V and GND to set the input voltage (undervoltage threshold) at
IN
which the device turns on. Pull up to V for always on.
IN
4
5
6
V
5V LDO Output. Bypass V
with 1µF ceramic capacitance to GND.
CC
CC
FeedbackꢀInput.ꢀForꢀfixedꢀoutputꢀvoltageꢀdevices,ꢀdirectlyꢀconnectꢀFB/VOꢀtoꢀtheꢀoutput.ꢀForꢀadjustableꢀ
output voltage devices, connect FB/VO to the center of the resistive divider between V
FB/VO
SS
and GND.
OUT
Soft-Start Input. Connect a capacitor from SS to GND to set the soft-start time.
External Loop Compensation. For adjustable output voltage (MAX17501G/H) connect to an RC network
from COMP to GND. See the External Loop Compensation for Adjustable Output Versions section for
moreꢀdetails.ꢀForꢀaꢀfixed-outputꢀvoltageꢀ(MAX17501A/B/E/F),ꢀthisꢀpinꢀisꢀaꢀnoꢀconnectꢀ(N.C.)ꢀandꢀshouldꢀ
be left unconnected.
7
8
N.C./COMP
Open-Drain RESET Output. The RESET output is driven low if FB drops below 92.5% of its set value.
RESET goes high 1024 clock cycles after FB rises above 95.5% of its set value. RESET is valid when
RESET
the device is enabled and V is above 4.5V.
IN
9
GND
LX
Analog Ground
Switching Node. Connect LX to the switching side of the inductor. LX is high impedance when the device
is in shutdown mode.
10
Exposed Pad. Connect to the GND pin of the IC. Connect to a large copper plane below the IC to improve
heat dissipation capability.
—
EP
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Block Diagram
V
CC
PGND
N DRIVER
5µA
SS
SS
LX
MAX17501
HICCUP
P DRIVER
V
IN
CURRENT
SENSE
V
CC
PWM
CLK
PWM, PFM
LOGIC
LDO
OSC
COMPARATOR
COMP
HICCUP
SLOPE
COMPENSATION
START
EN
FB
RESET
RESET
LOGIC
SS
900mV
REFERENCE
SWITCHOVER
LOGIC
COMP
N.C./COMP
G
M
INTERNAL
COMPENSATION
(FOR A, B, E, F VERSIONS)
GND
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
that disables the internal linear regulator when V
falls
CC
Detailed Description
below 3.7V (typical). The internal V
linear regulator can
CC
The MAX17501 synchronous step-down regulator oper-
ates from 4.5V to 60V and delivers up to 500mA load
current. Output voltage regulation accuracy meets ±1.7%
over temperature.
source up to 40mA (typical) to supply the device and to
power the low-side gate driver.
Operating Input Voltage Range
The device uses a peak-current-mode control scheme.
An internal transconductance error amplifier generates an
integrated error voltage. The error voltage sets the duty
cycle using a PWM comparator, a high-side current-sense
amplifier, and a slope-compensation generator. At each
rising edge of the clock, the high-side p-channel MOSFET
turns on and remains on until either the appropriate or
maximum duty cycle is reached, or the peak current limit
is detected.
The maximum operating input voltage is determined by
the minimum controllable on-time and the minimum oper-
ating input voltage is determined by the maximum duty
cycle and circuit voltage drops. The minimum and maxi-
mum operating input voltages for a given output voltage
should be calculated as:
V
+ (I
×(R
+ 0.47))
DCR
OUT
OUT(MAX)
V
=
IN(MIN)
D
MAX
During the high-side MOSFET’s on-time, the inductor
current ramps up. During the second half of the switching
cycle, the high-side MOSFET turns off and the low-side
n-channel MOSFET turns on and remains on until either
the next rising edge of the clock arrives or sink current
limit is detected. The inductor releases the stored energy
as its current ramps down, and provides current to the
+ (I
× 0.73)
OUT(MAX)
V
OUT
V
=
IN(MAX)
f
× t
ON(MIN)
SW (MAX)
where V
is the steady-state output voltage, I
OUT(MAX)
is the maximum load current, R
OUT
is the DC resistance
DCR
of the inductor, f
is the switching frequency (max-
is the worst-case minimum switch
SW(MAX)
output (the internal low R
pMOS/nMOS switches
DSON
imum) and t
ON(MIN)
ensure high efficiency at full load).
on-time (120ns). The following table lists the f
values to be used for calculation for different
versions of the MAX17501:
SW(MAX)
This device also integrates enable/undervoltage lockout
(EN/UVLO), adjustable soft-start time (SS), and open-
drain reset output (RESET) functionality.
and D
MAX
PART VERSION
MAX17501A/B/E/F/G
MAX17501H
f
(kHz)
D
MAX
SW (MAX)
PFM Operation
640
0.92
The A and B versions of the MAX17501 feature a PFM
scheme to improve light load efficiency. At light loads,
once the part enters PFM mode, the inductor current is
forced to a fixed peak of 125mA (typical) every clock cycle
until the output rises to 103.3% of nominal voltage. Once
output reaches 103.3% of nominal voltage, both high-
side and low-side FETs are turned off and the part enters
hibernate operation until the load discharges output to
101.3% of nominal voltage. Most of the internal blocks
are turned off in hibernate operation to save quiescent
current. Such an operation reduces the effective switch-
ing frequency of the converter at light loads, resulting in
reduced switching losses and improved light load effi-
ciency. The part naturally exits PFM mode when the load
current exceeds 62.5mA (typical).
320
0.965
Overcurrent Protection/HICCUP Mode
The device is provided with a robust overcurrent-
protection scheme that protects the device under over-
load and output short-circuit conditions. A cycle-by-cycle
peak current limit turns off the high-side MOSFET when-
ever the high-side switch current exceeds an internal limit
of 760mA (typ). A runaway current limit on the high-side
switch current at 780mA (typ) protects the device under
high input voltage, short-circuit conditions when there is
insufficient output voltage available to restore the inductor
current that built up during the on period of the step-down
converter. One occurrence of the runaway current limit
triggers a hiccup mode. In addition, if due to a fault condition,
output voltage drops to 71.14% (typ) of its nominal value
any time after soft-start is complete, hiccup mode is
triggered.
Linear Regulator (V
)
CC
An internal linear regulator (V ) provides a 5V nominal
CC
supply to power the internal blocks and the low-side
MOSFET driver. The output of the V
linear regulator
CC
In hiccup mode, the converter is protected by suspending
switching for a hiccup timeout period of 32,768 clock
shouldꢀ beꢀ bypassedꢀ withꢀ aꢀ 1μFꢀ ceramicꢀ capacitorꢀ toꢀ
GND. The device employs an undervoltage-lockout circuit
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
cycles. Once the hiccup timeout period expires, soft-start
is attempted again. This operation results in minimal
power dissipation under overload fault conditions.
is located distant from the device input, an electrolytic
capacitorꢀshouldꢀbeꢀaddedꢀinꢀparallelꢀtoꢀtheꢀ1μFꢀceramicꢀ
capacitor to provide necessary damping for potential
oscillations caused by the longer input power path and
input ceramic capacitor.
RESET Output
The device includes a RESET comparator to monitor the
output voltage. The open-drain RESET output requires
an external pullup resistor. RESET can sink 2mA of
current while low. RESET goes high (high impedance)
1024 switching cycles after the regulator output increases
above 95.5% of the designated nominal regulated
voltage. RESET goes low when the regulator output
voltage drops to below 92.5% of the nominal regulated
voltage. RESET also goes low during thermal shutdown.
Inductor Selection
Three key inductor parameters must be specified for
operation with the device: inductance value (L), inductor
saturation current (I
), and DC resistance (R
SAT
). The
DCR
switching frequency and output voltage determine the
inductor value as follows:
4.8 x V
OUT
L =
RESET is valid when the device is enabled and V is
f
IN
SW
above 4.5V.
where V
and f
are nominal values.
OUT
SW
Prebiased Output
Select a low-loss inductor closest to the calculated value
with acceptable dimensions and having the lowest pos-
When the device starts into a prebiased output, both the
high-side and low-side switches are turned off so the
converter does not sink current from the output. High-
side and low-side switches do not start switching until
the PWM comparator commands the first PWM pulse, at
which point switching commences first with the high-side
switch. The output voltage is then smoothly ramped up to
the target value in alignment with the internal reference.
sible DC resistance. The saturation current rating (I
)
SAT
of the inductor must be high enough to ensure that satu-
ration can occur only above the peak current-limit value
(I
(typ) = 0.76A for the device).
PEAK-LIMIT
Output Capacitor Selection
X7R ceramic output capacitors are preferred due to their
stability over temperature in industrial applications. The
output capacitor is usually sized to support a step load
of 50% of the maximum output current in the application,
so the output-voltage deviation is contained to ±3% of the
output-voltage change.
Thermal-Overload Protection
Thermal-overload protection limits total power dissipation
in the device. When the junction temperature of the device
exceeds +165°C, an on-chip thermal sensor shuts down
the device, allowing the device to cool. The thermal sensor
turns the device on again after the junction temperature
cools by 10°C. Soft-start resets during thermal shutdown.
Carefully evaluate the total power dissipation (see the
Power Dissipation section) to avoid unwanted triggering of
the thermal-overload protection in normal operation.
For fixed 3.3V and 5V output voltage versions, connect
aꢀ minimumꢀ ofꢀ 10μFꢀ (1206)ꢀ capacitorꢀ atꢀ theꢀ output.ꢀ Forꢀ
adjustable output voltage versions, the output capaci-
tance can be calculated as follows:
I
× t
RESPONSE
1
2
STEP
C
=
×
OUT
∆V
OUT
Applications Information
Input Capacitor Selection
0.33
1
t
≅
+
RESPONSE
The discontinuous input-current waveform of the buck
converter causes large ripple currents in the input capaci-
tor. The switching frequency, peak inductor current, and
the allowable peak-to-peak voltage ripple that reflects
back to the source dictate the capacitance requirement.
The device’s high switching frequency allows the use of
smaller value input capacitors. X7R capacitors are rec-
ommended in industrial applications for their temperature
stability.ꢀAꢀminimumꢀvalueꢀofꢀ1μFꢀshouldꢀbeꢀusedꢀforꢀtheꢀ
input capacitor. Higher values help reduce the ripple on
the input DC bus further. In applications where the source
f
f
SW
C
where I
is the load current step, t
responseꢀ timeꢀ ofꢀ theꢀ controller,ꢀ ΔV
output-voltage deviation, f is the target closed-loop cross-
is the switching frequency. Select
f to be 1/12th of f . Derating of ceramic capacitors with
DC-voltage must be considered while selecting the output
capacitor. Derating curves are available from all major
ceramic capacitor vendors.
is the
is the allowable
STEP
RESPONSE
OUT
C
over frequency, and f
SW
SW
C
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
select the parallel combination of R4 and R5, Rp to be
lessꢀthanꢀ30kΩ.ꢀOnceꢀRpꢀisꢀselected,ꢀcalculateꢀR4ꢀas:
Soft-Start Capacitor Selection
The MAX17501 implements adjustable soft-start opera-
tion to reduce inrush current. A capacitor connected from
the SS pin to GND programs the soft-start period.
Rp× V
OUT
R4 =
0.9
The selected output capacitance (C
) and the output
SEL
Calculate R5 as follows:
voltage (V
) determine the minimum required soft-start
OUT
R4× 0.9
capacitor as follows:
R5 =
(V
- 0.9)
OUT
CSS
-6 x CSEL x VOUT
The soft-start time (t ) is related to the capacitor
SS
Setting the Input Undervoltage Lockout Level
The device offers an adjustable input undervoltage-
lockout level. Set the voltage at which the device turns
connected at SS (C ) by the following equation:
SS
CSS
tSS
=
on with a resistive voltage-divider connected from V
5.55 x 10-6
IN
to GND (see Figure 2). Connect the center node of the
divider to EN/UVLO.
Adjusting Output Voltage
The MAX17501A/E and MAX17501B/F have preset
output voltages of 3.3V and 5.0V, respectively. Connect
FB/VO directly to the positive terminal of the output
capacitor (see the Typical Applications Circuits).
ChooseꢀR1ꢀtoꢀbeꢀ3.3MΩ,ꢀandꢀthenꢀcalculateꢀR2ꢀas:
R1×1.218
R2 =
(V
-1.218)
INU
The MAX17501G/H offer an adjustable output voltage
where V
is the voltage at which the device is required
INU
from 0.9V to 92%V . Set the output voltage with a resistive
to turn on. For adjustable output voltage devices, ensure
IN
voltage-divider connected from the positive terminal of the
that V is higher than 0.8 x V . If the EN/UVLO pin is
INU
OUT
output capacitor (V
) to GND (see Figure 1). Connect
driven from an external signal source, a series resistance
ofꢀminimumꢀ1kΩꢀisꢀrecommendedꢀtoꢀbeꢀplacedꢀbetweenꢀ
the signal source output and the EN/UVLO pin, to reduce
voltage ringing on the line.
OUT
the center node of the divider to FB/VO. To optimize
efficiency and output accuracy, use the following procedure
to choose the values of R4 and R5:
For MAX17501G, select the parallel combination of R4
andꢀR5,ꢀRpꢀtoꢀbeꢀlessꢀthanꢀ15kΩ.ꢀForꢀtheꢀMAX17501H,ꢀ
V
OUT
V
IN
R4
R1
R2
FB/VO
EN/UVLO
R5
GND
GND
Figure 1. Setting the Output Voltage
Figure 2. Adjustable EN/UVLO Network
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
At a particular operating condition, the power losses that
lead to temperature rise of the device are estimated as
follows:
External Loop Compensation for Adjustable
Output Versions
The MAX17501 uses peak current-mode control scheme
and needs only a simple RC network to have a stable,
high-bandwidth control loop for the adjustable output voltage
versions. The basic regulator loop is modeled as a power
modulator, an output feedback divider, and an error amplifier.
1
2
P
= (P
×( - 1)) - I
×R
OUT DCR
)
LOSS
(
OUT
η
P
= V
×I
OUT
OUT OUT
The power modulator has DC gain G
, with a pole
MOD(dc)
and zero pair. The following equation defines the power
modulator DC gain:
where P
the device, and R
inductor (refer to the Typical Operating Characteristics
in the evaluation kit data sheets for more information on
efficiency at typical operating conditions).
ꢀisꢀtheꢀoutputꢀpower,ꢀηꢀisꢀisꢀtheꢀefficiencyꢀofꢀ
OUT
is the DC resistance of the output
DCR
1
G
=
MOD(dc)
1
0.2
0.5 - D
f ×L
SW
+
+
R
V
LOAD
IN
SEL
For a typical multilayer board, the thermal performance
metrics for the 10-pin TDFN package are given as:
where R
= V
/I
, f
is the switching
LOAD
OUT OUT(MAX) SW
frequency, L
is the selected output inductance, D is
SEL
θ
θ
= 67.3°C W
= 18.2°C W
the duty ratio, D = V
V .
OUT/ IN
JA
JC
The compensation network is shown in Figure 3.
R can be calculated as:
Z
The junction temperature of the device can be estimated
at any given maximum ambient temperature (T
from the following equation:
R
= 12000× f × C
× V
SEL OUT
Z
C
)
A_MAX
where R ꢀisꢀinꢀΩ.ꢀChooseꢀf to be 1/12th of the switching
Z
C
frequency.
T
= T
+ θ ×P
A_MAX JA LOSS
(
)
J_MAX
C can be calculated as follows:
Z
If the application has a thermal-management system that
ensures that the exposed pad of the device is maintained
C
× G
MOD(dc)
SEL
C
=
Z
R
Z
at a given temperature (T ) by using proper heat
EP_MAX
sinks, then the junction temperature of the device can be
estimated at any given maximum ambient temperature as:
C can be calculated as follows:
P
1
C
=
P
π×R × f
Z
SW
T
= T
+ θ ×P
(
)
J_MAX
EP_MAX JC LOSS
Power Dissipation
The exposed pad of the IC should be properly soldered to
the PCB to ensure good thermal contact.
Junction temperature greater than +125°C degrades
operating lifetimes.
TO COMP PIN
R
Z
C
P
C
Z
Figure 3. External Compensation Network
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
3) The analog small-signal ground and the power ground
for switching currents must be kept separate. They
should be connected together at a point where switch-
ing activity is at minimum, typically the return terminal
PCB Layout Guidelines
Careful PCB layout is critical to achieve low switching loss-
es and stable operation. For a sample layout that ensures
first-pass success, refer to the MAX17501 evaluation kit
layouts available at www.maximintegrated.com. Follow
these guidelines for good PCB layout:
of the V
bypass capacitor. The ground plane should
CC
be kept continuous as much as possible.
4) A number of thermal vias that connect to a large
ground plane should be provided under the exposed
pad of the device, for efficient heat dissipation.
1) All connections carrying pulsed currents must be very
short and as wide as possible. The loop area of these
connections must be made very small to reduce stray
inductance and radiated EMI.
Figure 4 and Figure 5 show the recommended component
placement for MAX17501.
2) A ceramic input filter capacitor should be placed close
to the V pin of the device. The bypass capacitor for
IN
the V
pin should also be placed close to the V
CC
CC
pin. External compensation components should be
placed close to the IC and far from the inductor. The
feedback trace should be routed as far as possible
from the inductor.
V
PLANE
PGND PLANE
OUT
C4
L1
C1
LX PLANE
EP
V
IN
PLANE
R1
R2
RESET
C2
R4
C3
GND PLANE
VIAS TO BOTTOM SIDE PGND PLANE
VIAS TO BOTTOM SIDE V TRACK
OUT
VIAS TO BOTTOM SIDE GND PLANE
Figure 4. Recommended Component Placement for MAX17501A/B/E/F
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
V
PLANE
PGND PLANE
OUT
C4
L1
C1
LX PLANE
RESET
EP
V
IN
PLANE
R1
R2
R3
C2
R4
C3
C9
C5
R5
GND PLANE
VIAS TO BOTTOM SIDE PGND PLANE
VIAS TO BOTTOM SIDE V TRACK
OUT
VIAS TO BOTTOM SIDE GND PLANE
Figure 5. Recommended Component Placement for MAX17501G/H
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Typical Applications Circuits
L1
33µH
V
V
OUT
IN
V
LX
IN
3.3V, 500mA
24V
C1
C4
R1
1µF
10µF,
3.32MΩ
1206
1206
1
JU1 2
3
PGND
EN/UVLO
R2
866kΩ
MAX17501
GND
V
CC
C2
1µF
FB/VO
SS
C3
3300pF
L1 = LPS6235-333
N.C.
RESET
RESET
Figure 6. MAX17501A/E Application Circuit (3.3V Output, 500mA Maximum Load Current, 600kHz Switching Frequency)
L1
47µH
V
V
OUT
IN
V
LX
IN
5V, 500mA
24V
C1
1µF
1206
C4
10µF,
1206
R1
3.32MΩ
1
2
3
PGND
EN/UVLO
JU1
R2
866kΩ
MAX17501
GND
V
CC
C2
1µF
FB/VO
SS
C3
3300pF
L1 = LPS6235-473
N.C.
RESET
RESET
Figure 7. MAX17501B/F Application Circuit (5V Output, 500mA Maximum Load Current, 600kHz Switching Frequency)
Maxim Integrated
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
L1
100µH
V
V
OUT
IN
V
LX
IN
12V, 500mA
24V
C1
1µF
1206
C4
R1
4.7µF,
3.32MΩ
1206
1
JU1 2
3
PGND
EN/UVLO
R2
316kΩ
R4
174kΩ
MAX17501
GND
V
CC
C2
1µF
FB/VO
SS
C3
6800pF
R5
14kΩ
COMP
RESET
RESET
R3
C9
10pF
27.4kΩ
L1 = DR74-101-R
C5
1200pF
Figure 8. MAX17501G Application Circuit (12V Output, 500mA Maximum Load Current, 600kHz Switching Frequency)
L1
47µH
V
V
OUT
2.5V, 500mA
IN
V
LX
IN
24V
C1
2.2µF
1210
C4
22µF,
1210
R1
3.32MΩ
1
JU1 2
3
PGND
EN/UVLO
R2
1MΩ
R4
MAX17501
69.8kΩ
GND
V
CC
C2
1µF
FB/VO
SS
C3
6800pF
R5
39.2kΩ
COMP
RESET
RESET
R3
C9
47pF
20kΩ
C5
2200pF
L1 = LPS6235-473
Figure 9. MAX17501H Application Circuit (2.5V Output, 500mA Maximum Load Current, 300kHz Switching Frequency)
Maxim Integrated
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Ordering Information/Selector Guide
SWITCHING
FREQUENCY (kHz)
PART
PIN-PACKAGE
OUTPUT VOLTAGE (V)
MODE
MAX17501AATB+
MAX17501BATB+
MAX17501EATB+
MAX17501FATB+
MAX17501GATB+
MAX17501HATB+
10 TDFN-EP*
10 TDFN-EP*
10 TDFN-EP*
10 TDFN-EP*
10 TDFN-EP*
10 TDFN-EP*
3.3
600
600
600
600
600
300
PFM
PFM
5
3.3
PWM
PWM
PWM
PWM
5
Adjustable
Adjustable
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed pad.
Chip Information
PROCESS: BiCMOS
Package Information
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
TYPE
PACKAGE
CODE
OUTLINE LAND PATTERN
NO.
NO.
10 TDFN
T1032N+1
21-0429
90-0082
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MAX17501
60V, 500mA, Ultra-Small, High-Efficiency,
Synchronous Step-Down DC-DC Converter
Revision History
REVISION
NUMBER
REVISION
DATE
PAGES
CHANGED
DESCRIPTION
0
1
2
3
5/12
11/12
1/13
7/13
Initial release
—
Added MAX17501A, MAX17501B, MAX17501G, MAX17501H to data sheet
Added explanation on detailed condition for RESET
1–22
11, 14
3
Added output voltage accuracy for the MAX17501A and MAX17501B
Edited General Description, Benefits and Features, Pin Description, and
Adjusting Output Voltage sections
4
8/14
1, 11, 15
5
6
7
11/14
6/15
7/16
Removed automotive references from Applications section
Added output voltage to Typical Operating Characteristics section
Operating and junction temperature values updated
1
4–10, 14-17, 19, 20
14–16
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.
2016 Maxim Integrated Products, Inc.
│ 22
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