EVALUATION KIT AVAILABLE
Click here for production status of specific part numbers.
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
General Description
The Himalaya series of voltage regulator ICs and power
modules enable cooler, smaller, and simpler power
supply solutions. The MAXM17633, MAXM17634, and
MAXM17635 are a family of high-frequency synchronous
step-down DC-DC converter modules with integrated controller, MOSFETs, compensation components, and inductor, that operate over a wide input voltage range. The modules operate from 4.5V to 36V input and deliver up to 2A output current. MAXM17633 and MAXM17634 are fixed 3.3V
and 5V output modules, respectively. The MAXM17635
is an adjustable-output voltage (0.9V to 12V) module.
The modules significantly reduce design complexity,
manufacturing risks, and offer a true plug-and-play power
supply solution, reducing time to market.
The MAXM17633/MAXM17634/MAXM17635 modules
employ peak-current-mode control architecture. To reduce
input inrush current, the devices offer a programmable
soft-start time.
The MAXM17633/MAXM17634/MAXM17635 modules are
available in a low profile, compact 24-pin, 4mm x 4mm x
1.75mm, uSLIC™ package.
Applications
●●
●●
●●
●●
●●
●●
Industrial Control Power Supplies
General-Purpose Point-of-Load
Distributed Supply Regulation
Base Station Power Supplies
Programmable Logic Controller
High Voltage Single-Board Systems
Benefits and Features
● Easy to Use
• Wide 4.5V to 36V Input
• Adjustable 0.9V to 12V Output (MAXM17635)
• Fixed 3.3V and 5V Output Versions
(MAXM17633 and MAXM17634)
• 400kHz to 2.2MHz Adjustable Frequency with
External Clock Synchronization
• ±1.2% Feedback Accuracy
• Up to 2A Output Current
• Internally Compensated
• All Ceramic Capacitors
● High Efficiency
• Selectable PWM, PFM, or DCM Mode of Operation
• Shutdown Current as Low as 2.8μA (typ)
● Flexible Design
• Programmable Soft-Start and Prebias Startup
• Open-Drain Power Good Output (RESET Pin)
• Programmable EN/UVLO Threshold
● Robust Operation
• Hiccup Overcurrent Protection
• Overtemperature Protection
• -40°C to +125°C Ambient Operating Temperature/
-40°C to +150°C Junction Temperature
● Rugged
• Complies with CISPR22(EN55022) Class B
Conducted and Radiated Emissions
• Passes Drop, Shock, and Vibration Standards:
JESD22-B103, B104, B111
Ordering Information appears at end of data sheet.
Typical Application Circuit
VIN
7V TO 36V
IN
C1
4.7µF
VOUT
5V, 2A
OUT
EN/UVLO
C2
22µF
EXTVCC
VCC
VCC
C3
2.2µF
MODE/SYNC
C4
5600pF
FB
BST
SS
LX
RT
RESET
R3
19.1kΩ
uSLIC is a trademark of Maxim Integrated Products, Inc.
19-100594; Rev 0; 7/19
MAXM17634
SGND
PGND
C5
0.1µF
C1 = GRM31CR71H475KA12#
C2 = GRM32ER71E226KE15#
fSW = 1MHz
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Absolute Maximum Ratings
IN to PGND............................................................-0.3V to +40V
EN/UVLO to SGND.....................................-0.3V to (VIN + 0.3V)
LX, OUT to PGND.......................................-0.3V to (VIN + 0.3V)
EXTVCC to SGND................................................-5.5V to +6.5V
BST to PGND......................................................-0.3V to +46.5V
BST to LX..............................................................-0.3V to +6.5V
BST to VCC............................................................-0.3V to +40V
FB to SGND (MAXM17633 and MAXM17634).....-5.5V to +6.5V
FB to SGND (MAXM17635)..................................-0.3V to +6.5V
SS, MODE/SYNC, RESET, VCC, RT to SGND...-0.3V to +6.5V
PGND to SGND.....................................................-0.3V to +0.3V
Output Short-Circuit Duration.....................................Continuous
Operating Temperature Range (Note 1)............ -40°C to +125°C
Junction Temperature........................................ -40°C to +150°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +260°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.
Package Information
PACKAGE TYPE: 24-PIN uSLIC
Package Code
M244A4+1
Outline Number
21-100342
Land Pattern Number
90-100115
THERMAL RESISTANCE, FOUR-LAYER BOARD (Note 2)
Junction to Ambient (θJA)
25°C/W
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.
Note 1: Junction temperature greater than +125°C degrades operating lifetimes.
Note 2: Package thermal resistance is measured on an evaluation board with natural convection.
Electrical Characteristics
(VIN = VEN/UVLO = 24V, RRT = Unconnected, CVCC = 2.2µF, VSGND = VPGND = VMODE/SYNC = VEXTVCC = 0V; VFB = 3.67V
(MAXM17633), VFB = 5.5V (MAXM17634), VFB = 1V (MAXM17635), LX = SS = RESET = OPEN, VBST to VLX = 5V, TA = -40°C to
125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
36
V
4.5
μA
INPUT SUPPLY (VIN)
Input Voltage Range
Input Shutdown Current
Input Quiescent Current
www.maximintegrated.com
VIN
IIN-SH
4.5
VEN/UVLO = 0V (shutdown mode)
2.8
IQ_PFM
RRT = 19.1kΩ, MODE/SYNC = OPEN,
VEXTVCC = 5V
110
IQ_DCM
RRT = 19.1kΩ, MODE/SYNC = VCC,
VEXTVCC = 5V
710
IQ_PWM
RRT = 19.1kΩ, MODE/SYNC = SGND,
VEXTVCC = 5V
13
μA
mA
Maxim Integrated │ 2
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Electrical Characteristics (continued)
(VIN = VEN/UVLO = 24V, RRT = Unconnected, CVCC = 2.2µF, VSGND = VPGND = VMODE/SYNC = VEXTVCC = 0V; VFB = 3.67V
(MAXM17633), VFB = 5.5V (MAXM17634), VFB = 1V (MAXM17635), LX = SS = RESET = OPEN, VBST to VLX = 5V, TA = -40°C to
125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted.) (Note 3)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ENABLE/UVLO (EN/UVLO)
EN Threshold
EN Input Leakage Current
VENR
VEN/UVLO rising
1.19
1.215
1.26
VENF
VEN/UVLO falling
1.068
1.09
1.131
VEN/UVLO = 0V, TA = +25°C
-50
0
+50
1mA ≤ IVCC ≤ 25mA
4.75
5
5.25
6V ≤ VIN ≤ 36V, IVCC = 1mA
4.75
5
5.25
IEN
V
nA
VCC (LDO)
VCC Output Voltage Range
VCC Current Limit
VCC Dropout
VCC UVLO
VCC
IVCC-MAX
VCC-DO
VCC = 4.5V, VIN = 7.5V
30
V
mA
VIN = 4.5V, IVCC = 10mA
0.3
VVCC_UVR
VVCC rising
4.05
4.2
4.3
VVCC_UVF
VVCC falling
3.65
3.8
3.9
VEXTVCC rising
4.56
4.7
4.84
VEXTVCC falling
4.30
4.43
4.60
4.7
5
5.3
MODE/SYNC = SGND or
MODE/SYNC = VCC for MAXM17633
3.256
3.3
3.334
MODE/SYNC = SGND or
MODE/SYNC = VCC for MAXM17634
4.94
5
5.06
MODE/SYNC = SGND or
MODE/SYNC = VCC for MAXM17635
0.888
0.9
0.912
MODE/SYNC = OPEN for MAXM17633
3.256
3.36
3.44
MODE/SYNC = OPEN for MAXM17634
4.94
5.09
5.21
MODE/SYNC = OPEN for MAXM17635
0.888
0.915
0.938
V
V
EXTVCC
EXTVCC Switchover
Threshold
V
SOFT-START (SS)
Charging Current
ISS
μA
FEEDBACK (FB)
FB Regulation Voltage
FB Leakage Current
VFB-REG
IFB
For MAXM17633
23.2
For MAXM17634
23.2
For MAXM17635, TA = +25°C
-50
V
μA
+50
nA
MODE/SYNC
MODE Threshold
www.maximintegrated.com
VM-DCM
MODE/SYNC = VCC (DCM mode)
VM-PFM
MODE/SYNC = OPEN (PFM mode)
VM-PWM
MODE/SYNC = SGND (PWM mode)
VCC- 0.65
VCC/2
V
0.75
Maxim Integrated │ 3
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Electrical Characteristics (continued)
(VIN = VEN/UVLO = 24V, RRT = Unconnected, CVCC = 2.2µF, VSGND = VPGND = VMODE/SYNC = VEXTVCC = 0V; VFB = 3.67V
(MAXM17633), VFB = 5.5V (MAXM17634), VFB = 1V (MAXM17635), LX = SS = RESET = OPEN, VBST to VLX = 5V, TA = -40°C to
125°C, unless otherwise noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted.) (Note 3)
PARAMETER
SYNC Frequency Capture
Range
SYMBOL
fSYNC
CONDITIONS
fSW set by RRT
SYNC Pulse Width
SYNC Threshold
MIN
TYP
1.1 x fSW
MAX
1.4 x fSW
50
VIH
UNITS
kHz
ns
2.1
VIL
0.8
V
RT
Switching Frequency
VFB Undervoltage Trip Level
to Cause Hiccup
fSW
tON(MIN)
Minimum Off-Time
tOFF(MIN)
RESET Output Leakage Current
400
420
RRT = 40.2kΩ
475
500
525
RRT = OPEN
460
500
540
RRT = 8.06kΩ
1950
2200
2450
61.5
64.4
67.5
(Note 4)
Minimum On-Time
RESET Output Level Low
380
VFB-HICF
HICCUP Timeout
RESET
RRT = 50.8kΩ
VRESETL
IRESETLKG
32768
52
140
IRESET = 10mA
TA = TJ = 25ºC, VRESET = 5.5V
-100
kHz
%
Cycles
80
ns
160
ns
400
mV
+100
nA
FB Threshold for
RESET Rising
VFB-OKR
VFB Rising
93.8
95
97.8
%
FB Threshold for
RESET Falling
VFB-OKF
VFB Falling
90.5
92
94.6
%
RESET Delay after FB Reaches
Rising Threshold
1024
Cycles
165
°C
10
°C
THERMAL SHUTDOWN (TEMP)
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
Temperature rising
Note 3: Electrical specifications are production tested at TA = +25ºC. Specifications over the entire operating temperature range are
guaranteed by design and characterization.
Note 4: See the Overcurrent Protection/Hiccup Mode section for more details.
www.maximintegrated.com
Maxim Integrated │ 4
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, PWM MODE
toc001
100
toc002
100
90
90
80
80
80
70
70
VIN = 5V
50
VIN = 12V
40
VIN = 24V
30
VIN = 30V
VIN = 5V
60
VIN = 12V
50
VIN = 24V
40
VIN = 36V
30
20
10
0
0
80
70
70
VIN = 12V
VIN = 24V
VIN = 36V
30
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, PWM MODE
toc005
90
80
VIN = 7V
VIN = 12V
60
VIN = 24V
50
VIN = 36V
40
30
60
30
20
10
10
0
0
0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, PFM MODE
toc007
100
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, PFM MODE
toc008
100
90
80
80
80
70
70
VIN = 24V
VIN = 30V
70
VIN = 5V
60
VIN = 12V
50
VIN = 24V
40
VIN = 36V
30
EFFICIENCY (%)
VIN = 5V
VIN = 12V
EFFICIENCY (%)
90
60
30
20
10
0
0
LOAD CURRENT (A)
www.maximintegrated.com
0.01
0.1
LOAD CURRENT (A)
1
VIN = 24V
VIN = 36V
40
10
1
VIN = 12V
50
10
0.1
VIN = 5V
60
20
0.01
toc009
100
90
20
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, PFM MODE
30
VIN = 36V
40
10
40
VIN = 24V
50
20
LOAD CURRENT (A)
VIN = 18V
70
20
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
toc006
100
EFFICIENCY (%)
90
80
EFFICIENCY (%)
EFFICIENCY (%)
100
90
VIN = 5V
LOAD CURRENT (A)
MAXM17634/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, PWM MODE
toc004
50
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
100
EFFICIENCY (%)
0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
MAXM17633/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, PWM MODE
40
VIN = 36V
30
10
50
VIN = 24V
40
10
60
VIN = 12V
50
20
LOAD CURRENT (A)
VIN = 5V
60
20
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
toc003
70
EFFICIENCY (%)
60
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, PWM MODE
100
90
EFFICIENCY (%)
EFFICIENCY (%)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, PWM MODE
0
0.01
0.1
1
LOAD CURRENT (A)
Maxim Integrated │ 5
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17633/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, PFM MODE
toc010
100
90
80
80
70
70
60
VIN = 5V
50
VIN = 12V
40
VIN = 24V
30
EFFICIENCY (%)
90
VIN = 36V
80
VIN = 12V
60
VIN = 24V
50
VIN = 36V
40
30
60
30
20
10
10
0
0
0.01
0.1
0
1
toc014
100
80
70
70
70
VIN = 5V
VIN = 12V
30
VIN = 30V
20
VIN = 24V
VIN = 12V
40
VIN = 24V
30
20
10
10
0
0
0.01
VIN = 5V
0.1
1
EFFICIENCY (%)
90
80
EFFICIENCY (%)
90
60
0.01
0.1
100
80
toc017
80
VIN = 7V
60
VIN = 12V
50
VIN = 24V
40
VIN = 36V
30
70
60
30
20
10
10
10
0
0
LOAD CURRENT (A)
www.maximintegrated.com
1
0.01
0.1
LOAD CURRENT (A)
1
VIN = 24V
40
20
0.1
VIN = 18V
50
20
0.01
toc018
100
EFFICIENCY (%)
VIN = 24V
VIN = 36V
1
90
70
EFFICIENCY (%)
VIN = 12V
0.1
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, DCM MODE
80
VIN = 5V
30
0.01
LOAD CURRENT (A)
90
40
VIN = 36V
30
0
1
MAXM17634/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, DCM MODE
toc016
50
VIN = 24V
40
LOAD CURRENT (A)
90
60
VIN = 12V
50
10
MAXM17633/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, DCM MODE
70
VIN = 5V
60
20
VIN = 36V
LOAD CURRENT (A)
100
toc015
100
80
50
1
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, DCM MODE
90
60
0.1
LOAD CURRENT (A)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, DCM MODE
toc013
40
0.01
LOAD CURRENT (A)
100
50
VIN = 36V
40
10
1
VIN = 24V
50
20
0.1
VIN = 18V
70
20
0.01
toc012
100
VIN = 7V
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, DCM MODE
EFFICIENCY (%)
toc011
90
LOAD CURRENT (A)
EFFICIENCY (%)
MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, PFM MODE
EFFICIENCY (%)
100
EFFICIENCY (%)
MAXM17634/MAXM17635
EFFICIENCY vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, PFM MODE
0
VIN = 36V
0.01
0.1
1
LOAD CURRENT (A)
Maxim Integrated │ 6
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, PWM MODE
toc019
0.901
2.546
VIN = 30V
VIN = 24V
VIN = 12V
VIN = 5V
0.897
OUTPUT VOLTAGE (V)
0.899
1.516
1.514
VIN = 36V
VIN = 24V
1.512
1.510
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
2.538
VIN = 36V
VIN = 12V
VIN = 5V
2.530
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
LOAD CURRENT (A)
MAXM17633/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, PWM MODE
MAXM17634/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, PWM MODE
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, PWM MODE
toc022
toc023
5.080
3.30
VIN = 36V
VIN = 24V V = 12V
IN
VIN = 5V
12.09
OUTPUT VOLTAGE (V)
3.31
toc024
12.10
5.076
OUTPUT VOLTAGE (V)
3.32
5.072
VIN = 36V
VIN = 24V
5.068
VIN = 12V
VIN = 7V
12.08
12.07
3.29
5.064
12.06
3.28
5.060
12.05
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
LOAD CURRENT (A)
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, PFM MODE
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, PFM MODE
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, PFM MODE
toc025
VIN = 5V
VIN = 12V
VIN = 24V
VIN = 30V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
www.maximintegrated.com
2.62
1.54
1.52
1.50
1.48
VIN = 5V
VIN = 12V
VIN = 24V
VIN = 36V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
OUTPUT VOLTAGE (V)
0.92
toc027
2.65
1.56
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
toc026
1.58
0.94
0.86
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
0.96
0.88
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
VIN = 18V
VIN = 24V
VIN = 36V
0.90
VIN = 5V
VIN = 24V
LOAD CURRENT (A)
3.33
OUTPUT VOLTAGE (V)
2.542
2.534
VIN = 12V
0.896
toc021
2.550
1.518
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
toc020
1.520
0.900
0.898
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, PWM MODE
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, PWM MODE
2.59
2.56
VIN = 5V
2.53
VIN = 12V
VIN = 24V
2.50
VIN = 36V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (mA)
Maxim Integrated │ 7
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17633/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, PFM MODE
toc028
3.40
3.31
VIN = 12V
5.12
12.3
VIN = 7V
VIN = 12V
5.08
VIN = 24V
VIN = 24V
VIN = 36V
5.04
12.0
5.00
11.9
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
VIN = 5V
0.897
1.516
1.514
VIN = 36V
1.512
1.510
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
VIN = 12V
VIN = 24V
2.542
2.538
VIN = 36V
VIN = 24V
VIN = 5V
2.534
VIN = 5V
2.530
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
LOAD CURRENT (A)
MAXM17633/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 3.3V, fSW = 800kHz, DCM MODE
MAXM17634/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, DCM MODE toc035
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, DCM MODE
toc034
5.080
12.10
3.31
3.30
VIN = 36V
VIN = 24V
VIN = 12V
VIN = 5V
5.072
VIN = 36V
5.068
toc036
12.09
VIN = 12V
VIN = 24V
VIN = 7V
OUTPUT VOLTAGE (V)
5.076
OUTPUT VOLTAGE (V)
3.32
12.08
12.07
5.064
12.06
5.060
12.05
VIN = 36V
3.28
VIN = 12V
LOAD CURRENT (A)
3.33
OUTPUT VOLTAGE (V)
2.546
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
VIN = 12V
toc033
2.550
1.518
0.899
3.29
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 2.5V, fSW = 700kHz, DCM MODE
toc032
1.520
0.900
0.896
LOAD CURRENT (A)
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 1.5V, fSW = 600kHz, DCM MODE
toc031
0.901
VIN = 36V
VIN = 24V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 0.9V, fSW = 400kHz, DCM MODE
VIN = 24V
12.1
VIN = 18V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
VIN = 30V
12.2
VIN = 36V
LOAD CURRENT (A)
0.898
OUTUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
VIN = 5V
toc030
12.4
5.16
3.34
3.25
toc029
5.20
3.37
3.28
MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 12V, fSW = 1.8MHz, PFM MODE
MAXM17634/MAXM17635
OUTPUT VOLTAGE vs. LOAD CURRENT
VOUT = 5V, fSW = 1MHz, PFM MODE
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
www.maximintegrated.com
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
VIN = 24V
VIN = 18V
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
LOAD CURRENT (A)
Maxim Integrated │ 8
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
MAXM17633/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
toc037
toc039
toc038
10mV/div
VOUT(AC)
10mV/div
VOUT(AC)
1µs/div
1µs/div
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 12V, fSW = 1.8MHz, FULL LOAD, PWM MODE
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 2.5V, fSW = 700kHz, NO LOAD, PFM MODE
toc040
MAXM17633/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 3.3V, fSW = 800kHz, NO LOAD, PFM MODE
toc042
20mV/div
VOUT(AC)
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 12V, fSW = 1.8MHz, NO LOAD, PFM MODE
toc043
20mV/div
20ms/div
40ms/div
MAXM17634/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 5V, fSW = 1MHz, NO LOAD, PFM MODE
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 2.5V, fSW = 700kHz, 20mA LOAD, DCM MODE
toc045
toc044
50mV/div
www.maximintegrated.com
10mV/div
1µs/div
VOUT(AC)
400ns/div
20ms/div
VOUT(AC)
toc041
10mV/div
VOUT(AC)
VOUT(AC)
MAXM17634/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
VOUT(AC)
100mV/div
20ms/div
VOUT(AC)
10mV/div
4µs/div
Maxim Integrated │ 9
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17633/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 3.3V, fSW = 800kHz, 20mA LOAD, DCM MODE
MAXM17634/MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 5V, fSW = 1MHz, 20mA LOAD, DCM MODE
toc047
toc046
VOUT(AC)
MAXM17635
STEADY-STATE OUTPUT-VOLTAGE RIPPLE
VOUT = 12V, fSW = 1.8MHz, 20mA LOAD, DCM MODE
10mV/div
10mV/div
VOUT(AC)
4µs/div
toc048
4µs/div
1µs/div
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 2.5V, fSW = 700kHz, PWM MODE,
LOAD CURRENT STEPPED FROM 0A TO 1A
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 2.5V, fSW = 700kHz, PWM MODE,
LOAD CURRENT STEPPED FROM 1A TO 2A
toc049
toc050
VOUT(AC)
100mV/div
10mV/div
VOUT(AC)
VOUT(AC)
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 2.5V, fSW = 700kHz, PFM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
toc051
100mV/div
VOUT(AC)
100mV/div
1A/div
1A/div
IOUT
IOUT
1A/div
IOUT
200µs/div
200µs/div
200µs/div
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 2.5V, fSW = 700kHz, DCM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
MAXM17633/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 3.3V, fSW = 800kHz, PWM MODE,
LOAD CURRENT STEPPED FROM 0A TO 1A
MAXM17633/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 3.3V, fSW = 800kHz, PWM MODE,
LOAD CURRENT STEPPED FROM 1A TO 2A
toc053
toc052
VOUT(AC)
100mV/div
VOUT(AC)
toc054
100mV/div
VOUT(AC)
100mV/div
1A/div
1A/div
IOUT
200µs/div
www.maximintegrated.com
IOUT
1A/div
200µs/div
IOUT
200µs/div
Maxim Integrated │ 10
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17633/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 3.3V, fSW = 800kHz, PFM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
MAXM17633/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 3.3V, fSW = 800kHz, DCM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
MAXM17634/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 5V, fSW = 1MHz, PWM MODE,
LOAD CURRENT STEPPED FROM 0A TO 1A
toc056
toc055
VOUT(AC)
100mV/div
IOUT
1A/div
toc057
VOUT(AC)
100mV/div
1A/div
IOUT
100mV/div
VOUT(AC)
1A/div
IOUT
200µs/div
200µs/div
200µs/div
MAXM17634/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 5V, fSW = 1MHz, PWM MODE,
LOAD CURRENT STEPPED FROM 1A TO 2A
MAXM17634/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 5V, fSW = 1MHz, PFM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
MAXM17634/MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 5V, fSW = 1MHz, DCM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
toc058
toc059
VOUT(AC)
100mV/div
toc060
100mV/div
VOUT(AC)
VOUT(AC)
100mV/div
1A/div
IOUT
1A/div
IOUT
IOUT
1A/div
200µs/div
200µs/div
200µs/div
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 12V, fSW = 1.8MHz, PWM MODE,
LOAD CURRENT STEPPED FROM 0A TO 1A
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 12V, fSW = 1.8MHz, PWM MODE,
LOAD CURRENT STEPPED FROM 1A TO 2A
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 12V, fSW = 1.8MHz, PFM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
VOUT(AC)
toc063
toc062
toc061
200mV/div
VOUT(AC)
200mV/div
VOUT(AC)
500mV/div
1A/div
1A/div
IOUT
200µs/div
www.maximintegrated.com
IOUT
1A/div
IOUT
200µs/div
200µs/div
Maxim Integrated │ 11
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17635 LOAD-TRANSIENT RESPONSE
VOUT = 12V, fSW = 1.8MHz, DCM MODE,
LOAD CURRENT STEPPED FROM 20mA TO 1A
MAXM17635 STARTUP THROUGH ENABLE
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
toc066
toc065
toc064
5V/div
VOUT(AC)
500mV/div
20V/div
LX
1A/div
5V/div
RESET
20V/div
VOUT
1V/div
RESET
5V/div
1ms/div
100μs/div
MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 2.5V, fSW = 700kHz, 20mA LOAD, PFM MODE
MAXM17633/MAXM17635 STARTUP THROUGH ENABLE
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
200µs/div
MAXM17635 STARTUP THROUGH ENABLE
VOUT = 2.5V, fSW = 700kHz, 20mA LOAD, PFM MODE
LX
1V/div
VOUT
IOUT
5V/div
EN/UVLO
EN/UVLO
toc068
toc067
toc069
5V/div
5V/div
EN/UVLO
EN/UVLO
20V/div
1V/div
LX
5V/div
LX
20V/div
EN/UVLO
20V/div
LX
2V/div
VOUT
5V/div
RESET
VOUT
1V/div
VOUT
RESET
5V/div
RESET
1ms/div
MAXM17633/MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
5V/div
20ms/div
1ms/div
MAXM17633/MAXM17635 STARTUP THROUGH ENABLE
VOUT = 3.3V, fSW = 800kHz, 20mA LOAD, PFM MODE
MAXM17633/MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 3.3V, fSW = 800kHz, 20mA LOAD, PFM MODE
toc070
toc071
toc072
5V/div
EN/UVLO
5V/div
LX
20V/div
EN/UVLO
5V/div
EN/UVLO
20V/div
LX
20V/div
LX
2V/div
VOUT
2V/div
VOUT
RESET
5V/div
RESET
100μs/div
www.maximintegrated.com
5V/div
1ms/div
VOUT
2V/div
RESET
5V/div
20ms/div
Maxim Integrated │ 12
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17634/MAXM17635 STARTUP THROUGH ENABLE
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635 STARTUP THROUGH ENABLE
VOUT = 5V, fSW = 1MHz, 20mA LOAD, PFM MODE
toc074
toc073
toc075
5V/div
EN/UVLO
5V/div
5V/div
EN/UVLO
20V/div
LX
LX
20V/div
EN/UVLO
20V/div
LX
2V/div
2V/div
VOUT
5V/div
RESET
VOUT
2V/div
VOUT
RESET
5V/div
RESET
5V/div
1ms/div
100μs/div
1ms/div
MAXM17634/MAXM17635 SHUTDOWN THROUGH ENABLE
VOUT = 5V, fSW = 1MHz, 20mA LOAD, PFM MODE
MAXM17635 STARTUP THROUGH IN
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
MAXM17635 SHUTDOWN THROUGH IN
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
toc077
toc076
toc078
20V/div
EN/UVLO
LX
5V/div
VIN
20V/div
LX
20V/div
VIN
20V/div
LX
20V/div
2V/div
1V/div
VOUT
2V/div
VCC
VCC
2V/div
RESET
5V/div
VOUT
VOUT
1V/div
20ms/div
1ms/div
2ms/div
MAXM17635 STARTUP THROUGH IN
VOUT = 2.5V, fSW = 700kHz, 20mA LOAD, PFM MODE
MAXM17635 SHUTDOWN THROUGH IN
VOUT = 2.5V, fSW = 700kHz, 20mA LOAD, PFM MODE
MAXM17633/MAXM17635 STARTUP THROUGH IN
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
toc079
toc081
toc080
20V/div
VIN
20V/div
LX
20V/div
VIN
20V/div
VIN
LX
20V/div
LX
20V/div
2V/div
2V/div
1V/div
2V/div
VCC
VCC
2V/div
VCC
VOUT
VOUT
1V/div
VOUT
1ms/div
www.maximintegrated.com
20ms/div
1ms/div
Maxim Integrated │ 13
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17633/MAXM17635 SHUTDOWN THROUGH IN
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
MAXM17633/MAXM17635 STARTUP THROUGH IN
VOUT = 3.3V, fSW = 800kHz, 20mA LOAD, PFM MODE
toc082
MAXM17633/MAXM17635 SHUTDOWN THROUGH IN
VOUT = 3.3V, fSW = 800kHz, 20mA LOAD, PFM MODE
toc084
toc083
20V/div
VIN
20V/div
VIN
LX
20V/div
LX
VIN
20V/div
LX
20V/div
VCC
VCC
2V/div
VOUT
VOUT
2V/div
20V/div
2V/div
2V/div
VCC
2V/div
VOUT
2V/div
2ms/div
1ms/div
20ms/div
MAXM17634/MAXM17635 STARTUP THROUGH IN
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635 SHUTDOWN THROUGH IN
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635 STARTUP THROUGH IN
VOUT = 5V, fSW = 1MHz, 20mA LOAD, PFM MODE
toc086
toc085
toc087
20V/div
VIN
20V/div
LX
20V/div
VIN
20V/div
VIN
LX
20V/div
LX
20V/div
2V/div
2V/div
2V/div
2V/div
VCC
VCC
2V/div
VCC
VOUT
VOUT
2V/div
VOUT
1ms/div
2ms/div
1ms/div
MAXM17634/MAXM17635 SHUTDOWN THROUGH IN
VOUT = 5V, fSW = 1MHz, 20mA LOAD, PFM MODE
MAXM17633/MAXM17635
STARTUP THROUGH ENABLE (2.5V PREBIAS)
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635
STARTUP THROUGH ENABLE (3.3V PREBIAS)
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
toc088
toc089
toc090
5V/div
VIN
20V/div
LX
20V/div
5V/div
EN/UVLO
EN/UVLO
LX
20V/div
LX
20V/div
2V/div
2V/div
VCC
2V/div
VOUT
2V/div
20ms/div
www.maximintegrated.com
VOUT
5V/div
RESET
5V/div
VOUT
RESET
1ms/div
1ms/div
Maxim Integrated │ 14
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
MAXM17635
STARTUP THROUGH ENABLE (5V PREBIAS)
VOUT = 12V, fSW = 1.8MHz, FULL LOAD, PWM MODE
toc091
MAXM17635
OUTPUT SHORT IN STEADY STATE
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
toc092
toc093
5V/div
VIN
20V/div
5V/div
50mV/div
VOUT
2V/div
VOUT
20V/div
LX
VOUT
20V/div
5V/div
SHORT
EN/UVLO
LX
MAXM17635
OUTPUT SHORT DURING STARTUP
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
20V/div
LX
5V/div
RESET
IOUT
1A/div
IOUT
20mA/div
1ms/div
20ms/div
20ms/div
MAXM17633/MAXM17635
OUTPUT SHORT IN STEADY STATE
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
MAXM17633/MAXM17635
OUTPUT SHORT DURING STARTUP
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635
OUTPUT SHORT IN STEADY STATE
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
toc095
toc094
20V/div
5V/div
50mV/div
VOUT
VOUT
20V/div
IOUT
1A/div
5V/div
VOUT
2V/div
LX
5V/div
SHORT
VIN
SHORT
toc096
LX
20V/div
20mA/div
IOUT
10ms/div
MAXM17634/MAXM17635 EXT CLOCK SYNC
VOUT = 5V, fSW = 1MHz, fSYNC = 1.4MHz,
FULL LOAD, PWM MODE
MAXM17634/MAXM17635
OUTPUT SHORT DURING STARTUP
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
MAXM17634/MAXM17635 EXT CLOCK SYNC
VOUT = 5V, fSW = 1MHz, fSYNC = 1.4MHz,
FULL LOAD, PWM MODE
toc098
toc097
1A/div
IOUT
10ms/div
10ms/div
20V/div
LX
toc099
20V/div
VIN
VSYNC
VOUT
5V/div
VSYNC
5V/div
50mV/div
VOUT(AC)
LX
20V/div
IOUT
50mA/div
10ms/div
www.maximintegrated.com
LX
20V/div
2µs/div
20mV/div
20V/div
LX
20µs/div
Maxim Integrated │ 15
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Operating Characteristics (continued)
(VEN/UVLO = VIN = 24V, VSGND = VPGND = 0V, CINTVCC = 2.2μF, CBST = 0.1μF, CSS = 5600pF, TA = -40°C to +125°C, unless otherwise
noted. Typical values are at TA = +25°C. All voltages are referenced to SGND, unless otherwise noted. The circuit values for different
output-voltage applications are as in Table 1, unless otherwise noted.)
125
20
10
0
50
PHASE
-10
GAIN
125
30
125
100
20
100
20
100
75
10
75
10
0
50
CROSSOVER FREQUENCY = 59.862kHz
PHASE MARGIN = 68.352°
1k
10k
100k
PHASE
GAIN
-10
0
-30
-40
30
25
-20
-25
-30
-50
-40
CROSSOVER FREQUENCY = 88.858kHz
PHASE MARGIN = 58.211°
1k
10k
20
100
10
75
0
50
PHASE
25
GAIN
0
CROSSOVER FREQUENCY = 60.752kHz
PHASE MARGIN = 74.878°
1k
10k
-30
-50
-40
1k
100k
10k
-25
-50
100k
FREQUENCY (Hz)
2.0
OUTPUT CURRENT (A)
GAIN (dB)
125
-40
-25
0
CROSSOVER FREQUENCY = 85.608kHz
PHASE MARGIN = 66.088°
toc104
2.5
150
30
25
-20
MAXM17633/MAXM17634/MAXM17635
OUTPUT CURRENT vs. AMBIENT TEMPERATURE
PHASE (°)
toc103
40
-30
100k
50
GAIN
-10
0
150
75
PHASE
0
FREQUENCY (Hz)
MAXM17635 BODE PLOT
VOUT = 12V, fSW = 1.8MHz, FULL LOAD, PWM MODE
-20
25
-20
FREQUENCY (Hz)
-10
toc102
40
GAIN (dB)
30
toc101
150
GAIN (dB)
40
PHASE (°)
GAIN (dB)
150
MAXM17634/MAXM17635 BODE PLOT
VOUT = 5V, fSW = 1MHz, FULL LOAD, PWM MODE
PHASE (°)
toc100
40
MAXM17633/MAXM17635 BODE PLOT
VOUT = 3.3V, fSW = 800kHz, FULL LOAD, PWM MODE
PHASE (°)
MAXM17635 BODE PLOT
VOUT = 2.5V, fSW = 700kHz, FULL LOAD, PWM MODE
1.5
VOUT = 3.3V
1.0
VOUT = 5V
0.5
-25
VOUT = 12V
-50
0.0
25
FREQUENCY (Hz)
35
45 55 65 75 85 95 105 115 125
AMBIENT TEMPERATURE (°C)
MEASURED ON MAXM17633/MAXM17634/MAXM17635 EV KIT
TUV Rheinland
Final_ScanV
Maxim Ic_Buck Converter_Max MRADIATED
17635 3.3V Output
MAXM17633/MAXM17635
EMISSIONS
Final_ScanHPLOT
RE 30MHz-1GHz
VOUT
= 3.3V, fSW = 800kHz, FULL LOAD, PWM
Limit MODE
toc107
70.0
70
TUV Rheinland
Final_ScanV
Maxim Ic_Buck Converter_Max MRADIATED
17635 5V OutputEMISSIONS
MAXM17634/MAXM17635
Final_ScanHPLOT
30MHz-1GHz
VREOUT
= 5V, fSW = 1MHz, FULL LOAD, PWMLimitMODE
60.0
60
CISPR-22 CLASS B QP LIMIT
30.0
30
HORIZONTAL SCAN
20.0
20
10.0
10
00
-10.0
-10
30.0M
30M
VERTICAL SCAN
100.0M
100M
1.0G
1G
Frequency (Hz)
FREQUENCY (Hz)
50.0
50
CISPR-22 CLASS B QP LIMIT
40.0
40
30.0
30
HORIZONTAL SCAN
20.0 VERTICAL SCAN
20
10.0
10
00
-10.0
-10
30.0M
30M
100.0M
100M
1.0G
1G
Frequency (Hz)
FREQUENCY (Hz)
RE 30MHz-1GHz_0-360Deg_90Deg step_1-4mtr Height_Quick Scan_Config 5.TIL
RE 30MHz-1GHz_0-360Deg_90Deg step_1-4mtr Height_Quick Scan_Config 4.TIL
07:48:07 PM, Wednesday, April 17, 2019
07:22:55 PM, Wednesday, April 17, 2019
MEASURED ON MAXM17633 EV KIT
www.maximintegrated.com
MAGNITUDE (dBµV/m)
50.0
50
Am p litu d e (d Bu V /m )
MAGNITUDE (dBµV/m)
Am p litu d e (d Bu V /m )
60.0
60
40.0
40
toc108
70.0
70
MEASURED ON MAXM17634 EV KIT
Maxim Integrated │ 16
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Pin Configuration
LX
PGND
PGND
PGND
PGND
IN
TOP VIEW
24
23
22
21
20
19
LX
1
18 IN
BST
2
17 IN
EXTVCC
3
OUT
4
OUT
5
14 RESET
OUT
6
13 VCC
10
11
12
MODE/
SYNC
9
SS
FB
15 EV/UVLO
SGND
8
16 IN
RT
7
OUT
MAXM17633/
MAXM17634/
MAXM17635
TQFN
4mm x 4mm
‘ ’ INDICATES PIN 1 OF THE MODULE
Pin Description
PIN
NAME
1, 24
LX
2
BST
3
EXTVCC
4-7
OUT
8
FB
Output Feedback Connection. Connect FB to the output-voltage node (OUT) for MAXM17633
and MAXM17634. Connect FB to the center of the external resistor-divider from OUT to SGND
for MAXM17635 to set the output voltage.
9
RT
Programmable Switching Frequency Input. Connect a resistor from RT to SGND to set the
switching frequency of the module between 400kHz and 2.2MHz. Leave RT open for the default
500kHz frequency. See the Setting the Switching Frequency (RT) section for more details.
10
SGND
11
SS
www.maximintegrated.com
FUNCTION
Switching Node Pins.
Bootstrap Flying Capacitor. Connect a 0.1μF ceramic capacitor between BST and LX.
External Power Supply Input. Reduces the Internal-LDO Loss. Connect it to OUT when it is
programmed for 5V output. When EXTVCC is not used, connect it to SGND.
Module Output Pins. Connect the output capacitor COUT from OUT to PGND.
Signal Ground Pin.
Soft-Start Input. Connect a capacitor from SS to SGND to set the soft-start time.
Maxim Integrated │ 17
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Pin Description (continued)
PIN
NAME
FUNCTION
MODE/SYNC Pin. Configures the module to operate in PWM, PFM, or DCM mode of
operation. Leave MODE/SYNC unconnected for PFM operation (pulse skipping at light loads).
Connect MODE/SYNC to SGND for constant-frequency PWM operation at all loads. Connect
MODE/SYNC to VCC for DCM operation at light loads.The module can be synchronized to an
external clock using this pin. See the Mode Selection and External Synchronization
(MODE/SYNC) section for more details.
12
MODE/SYNC
13
VCC
14
RESET
Open-Drain RESET Output. The RESET output is driven low if FB drops below 92% of its set
value. RESET goes high 1024 cycles after FB rises above 95% of its set value.
15
EN/UVLO
Enable/Undervoltage Lockout Pin. Drive EN/UVLO high to enable the output. Connect
EN/UVLO to the center of the resistor-divider between IN and SGND to set the input voltage
at which the part turns on. Connect EN/UVLO to the IN pin for always-on operation.
Pull EN/UVLO low for disabling the module.
16-19
IN
Power-Supply Input Pins. 4.5V to 36V input-supply range. Decouple to PGND with a capacitor;
place the capacitor close to the IN and PGND pins.
20-23
PGND
Power Ground Pins. Connect externally to the power ground plane. Refer to the MAXM17633
Evaluation Kit data sheet for a layout example.
—
EP
www.maximintegrated.com
5V LDO Output of the module. Bypass VCC with a 2.2μF ceramic capacitor to SGND.
Exposed Pad. Connect EP to the PGND pins of module. Also, connect EP to a large PGND plane
with several thermal vias for the best thermal performance. Refer to the MAXM17633 EV Kit data
sheet for an example of the correct method for EP connection and thermal vias.
Maxim Integrated │ 18
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Functional Diagrams
MAXM17633/MAXM17634/MAXM17635
IN
BST
LX
ENOK
EN/UVLO
1.215V
RT
PWM/PFM/HICCUP
LOGIC
OSCILLATOR
3.3µH
HICCUP
OUT
MODE
SELECTION
MODE/SYNC
PGND
S1
IN
EXTVCC
S3
LDO
ERROR AMPLIFIER/
LOOP COMPESATION
THERMAL SHUTDOWN
VCC
SLOPE
COMPENSATION
HICCUP
FB
SGND
CURRENT
SENSE
RESET
SOFT-START
LOGIC
SS
S2
R1
R2
ENOK
FB
RESET
LOGIC
S1: CLOSED; S2, S3: OPEN FOR MAXM17635
S1: OPEN; S2, S3: CLOSED FOR MAXM17633/MAXM17634
R1: 176.6kΩ, R2: 38.8kΩ FOR MAXM17634
R1: 103.4kΩ, R2: 38.8kΩ FOR MAXM17633
www.maximintegrated.com
Maxim Integrated │ 19
MAXM17633/MAXM17634/
MAXM17635
Detailed Description
The MAXM17633, MAXM17634, and MAXM17635 are a
family of high-frequency synchronous step-down DC-DC
converter modules, with integrated controller, MOSFETs,
compensation components, and inductor that operate
over a wide input voltage range. The modules deliver
an output current of up to 2A. The MAXM17633 and
MAXM17634 are fixed 3.3V and 5V output modules,
respectively. The MAXM17635 is an adjustable-output
voltage (0.9V to 12V) module. When EN/UVLO and the
VCC threshold are ascertained, an internal power-up
sequence ramps up the error-amplifier reference, resulting in an output-voltage soft-start.
The FB pin monitors the output voltage through a resistor
divider. The RESET pin transitions to a high-impedance
state 1024 clock cycles after the output voltage reaches
95% of regulation. The modules select either PFM or
forced-PWM or DCM mode depending on the state of the
MODE/SYNC pin at power-up. By pulling the EN/UVLO
pin low, the modules enter shutdown mode and consume
only 2.8μA (typ) of standby current.
The modules employ peak-current-mode control architecture. An internal error amplifier compares the feedback
voltage to a fixed reference voltage and generates an
error voltage. The error voltage is compared to the sum
of the current-sense voltage and slope-compensation
voltage by a PWM comparator to set the on-time. At each
rising edge of the clock, the high-side MOSFET turns on
and remains on until either the appropriate or maximum
duty cycle is reached, or the peak current limit is detected.
During the high-side MOSFET’s on-time, the internal
inductor current ramps up. During the second half of the
switching cycle, the high-side MOSFET turns off and the
low-side MOSFET turns on. The inductor in the module
releases the stored energy as its current ramps down and
provides current to the output.
Mode Selection and
External Synchronization (MODE/SYNC)
The modules support PWM, PFM, and DCM modes
of operation. The modules enter the required mode of
operation based on the setting of the MODE/SYNC pin
as detected within 1.5ms after VCC and EN/UVLO voltages exceed their respective rising thresholds (VCC_UVR,
VENR). If the state of the MODE/SYNC pin is open, the
modules operate in PFM mode at light loads. If the state
of the MODE/SYNC pin is low (lower than VM_PWM),
the modules operate in constant-frequency PWM mode
at all loads. If the state of the MODE/SYNC pin is high
www.maximintegrated.com
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
(higher than VM_DCM), the modules operate in constantfrequency DCM mode at light loads. State changes on the
MODE/SYNC pin are ignored during normal operation.
The internal oscillator of the modules can be synchronized to an external clock signal through the MODE/
SYNC pin when the part is programmed to DCM or PWM
mode of operation. SYNC is not supported in PFM mode.
The internal oscillator frequency changes to an external
clock frequency when 16 external clock rising edges are
detected on the MODE/SYNC pin. The external clock
frequency must be between 1.1 x fSW and 1.4 x fSW,
where fSW is the switching frequency programmed by
the resistor connected between the RT pin to SGND. The
external clock pulse width should be greater than 50ns
and the off time duration should be greater than 160ns.
See the Mode Sync section in the Electrical Characteristics
table for details.
PWM Mode Operation
In PWM mode, the internal inductor current is allowed
to go negative. PWM operation is useful in frequency
sensitive applications and provides fixed switching
frequency operation at all loads. However, the PWM
mode of operation gives lower efficiency at light loads
compared to PFM and DCM modes of operation.
PFM Mode Operation
PFM mode of operation disables negative internal inductor current and additionally skips pulses at light loads for
high efficiency. In PFM mode, the module output current
is forced to a fixed peak of IPFM (1.17A typ) every clock
cycle until the output rises to 102.3% of the set nominal
output voltage. Once the output reaches 102.3% of the
set nominal output voltage, both the high-side and lowside FETs are turned off and the device enters hibernate
operation until the load discharges the output to 101.1%
of the set nominal output voltage. Most of the internal
blocks are turned off in hibernate operation to save
quiescent current. After the output falls below 101.1%
of the set nominal output voltage, the module comes
out of hibernate operation, turns on all internal blocks,
and again commences the process of delivering pulses
of energy to the output until it reaches 102.3% of the
set nominal output voltage. The advantage of the PFM
mode is higher efficiency at light loads because of lower
quiescent current drawn from supply. The disadvantage is
that the output-voltage ripple is higher compared to PWM
or DCM modes of operation and switching frequency is
not constant at light loads.
Maxim Integrated │ 20
MAXM17633/MAXM17634/
MAXM17635
DCM Mode Operation
DCM mode of operation features constant frequency
operation down to lighter loads than PFM mode, by
disabling negative internal inductor current at light loads.
DCM operation offers efficiency performance that lies
between PWM and PFM modes. The output voltage ripple
in DCM mode is comparable to PWM mode and relatively
lower compared to PFM mode.
Linear Regulator (VCC and EXTVCC)
The modules have an internal low dropout (LDO) regulator that powers VCC from IN. This LDO is enabled
during power-up or when EN/UVLO is above 0.75V (typ).
An internal switch connects the EXTVCC to VCC. The
switch is open during power-up. If VCC is above its UVLO
threshold and if EXTVCC is greater than 4.7V (typ) then,
the internal LDO is disabled and VCC is powered from
EXTVCC. Powering VCC from EXTVCC increases efficiency at higher input voltages. Typical VCC output voltage is 5V. Bypass VCC to SGND with a 2.2µF low-ESR
ceramic capacitor. VCC powers the internal blocks and
the low-side MOSFET driver, and recharges the external
bootstrap capacitor.
The modules employ an undervoltage lockout circuit that
forces the converter off when VCC falls below VCC-UVF
(3.8 typ). The modules can be immediately enabled again
when VCC > VCC-UVR (4.2 typ). The 400mV UVLO hysteresis prevents chattering on power-up/power-down.
In applications where the module output is connected
to the EXTVCC pin, if the output is shorted to ground
then the transfer from EXTVCC to internal LDO happens
seamlessly without any impact on the normal functionality. Connect the EXTVCC pin to SGND when not in use.
Enable/Undervoltage Lockout (EN/UVLO),
Soft-Start (SS)
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
RESET Output
The modules include an open-drain RESET pin to
monitor the status of output voltage. The RESET pin
requires an external pullup resistor. RESET goes high
impedance with a delay of 1024 switching cycles after the
regulator output voltage increases above 95% of its nominal set value and goes low when the output voltage falls
below 92% of its nominal set value. RESET also goes low
during thermal shutdown or when the EN/UVLO pin goes
below the falling threshold.
Prebiased Output
The modules are capable of soft-start into a prebiased
output, without discharging the output capacitor in all
modes. Such a feature is useful in applications where
digital integrated circuits with multiple rails are powered.
Overcurrent Protection/Hiccup Mode
The modules are provided with a robust overcurrent protection (OCP) scheme that protects the modules under overload and output short-circuit conditions. A cycle-by-cycle
peak current limit turns off the high-side MOSFET whenever the high-side switch current exceeds an internal limit
of IPEAK-LIMIT (3.55A typ). A runaway current limit on the
high-side switch current at the IRUNAWAY-LIMIT (4.43A typ)
protects the device under high input voltage, output shortcircuit conditions when there is insufficient output voltage
available to restore the module current that was built up
during the on period of the module. One occurrence of the
runaway current limit triggers a hiccup mode. In addition,
due to any fault, if the feedback voltage drops below 64%
of the nominal value any time after soft-start is completed,
the hiccup mode is activated. In hiccup mode, the modules
are protected by suspending switching for a hiccup timeout
period of 32,768 clock cycles of half the switching frequency. Once the hiccup timeout period expires, soft-start
is attempted again. Note that when soft-start is attempted
under overload condition, if feedback voltage does not
exceed 64% of the nominal value, the modules continue to
switch at half the programmed switching frequency for the
time duration of the programmed soft-start time and 1024
clock cycles. Hiccup mode of operation ensures low power
dissipation under output short-circuit conditions.
When EN/UVLO voltage is above 1.215V (typ), the
internal error-amplifier reference voltage of the module
starts to ramp up. The duration of the soft-start ramp is
programmable through the choice of an external capacitor put at the SS pin, allowing a smooth increase of the
output voltage. Driving EN/UVLO low disables both power
MOSFETs, as well as other internal circuitry, and reduces
The MAXM17633/34/35 are designed to support a maxiIN quiescent current to below 2.8μA (typ). EN/UVLO can
mum load current of 2A. The inductor ripple current is
be used as an input-voltage UVLO adjustment input. An
calculated as follows:
external voltage-divider between IN and EN/UVLO to
SGND adjusts the input voltage at which the device turns
V − VOUT − 0.233 × I OUT
=
∆ I IN
on or turns off. If input UVLO programming is not
desired,
×
L × f SW
connect EN/UVLO to IN (see the Electrical Characteristics
table for EN/UVLO rising and falling threshold voltages).
www.maximintegrated.com
VOUT + 0.188 × I OUT
VIN − 0.045 × I OUT
Maxim Integrated │ 21
MAXM17633/MAXM17634/
MAXM17635
where:
The input capacitor RMS current requirement (IRMS) is
defined by the following equation:
VOUT = Steady-state output voltage
VIN = Operating input voltage for given VOUT
fSW = Switching frequency in MHz
L = Power module output inductance (3.3μH ±20%)
IOUT = Output (load) current
The following condition should be satisfied at the desired
load current, IOUT:
I OUT +
Applications Information
The minimum and maximum operating input voltages for
a given output voltage setting is calculated as follows:
VOUT + (0.188 × I OUT )
(
)
+ 0.045 × I OUT
VOUT
t ON(MIN) × f SW
Also, for duty cycle > 0.5,
VIN(MIN) > 4.25 x VOUT + 0.65 x IOUT − 33.48 x fSW
where:
VOUT = Steady-state output voltage,
IOUT = Load current,
tOFF(MIN) = Minimum OFF time (160ns),
tON(MIN) = Minimum ON time (80ns).
fSW = Switching frequency in MHz.
Selection of Input capacitor
The input filter capacitor reduces peak currents drawn
from the power source and reduces noise and voltage
ripple on the input caused by the switching of the module.
2
Choose an input capacitor that exhibits less than +10°C
temperature rise at the RMS input current for optimal
long-term reliability. Use low-ESR ceramic capacitors with
high-ripple-current capability at the input. X7R capacitors
are recommended in industrial applications for their temperature stability. Calculate the input capacitance using
the following equation:
(1 − D)
η × f SW × ∆VIN
where:
D = Duty ratio of the converter
fSW = Switching frequency
ΔVIN = Allowable input voltage ripple
η = Efficiency
In applications where the source is located away and
distant from the device input, an appropriate electrolytic
capacitor should be added to provide necessary damping
of potential oscillations caused by the inductance of the
input power path and input ceramic capacitor.
Selection of Output capacitor
Small ceramic X7R-grade capacitors are sufficient and
recommended for output-voltage generation. The output
capacitor has two functions. It provides smooth output
voltage and, stores sufficient energy to support the output voltage under load transient conditions stabilizing the
internal control loop of the module. Usually the output
capacitor is sized to support a load step of 50% of the
maximum output current in the application, such that the
output-voltage deviation is less than 3%. Required output
capacitance can be calculated from the following equation:
C OUT =
www.maximintegrated.com
I OUT ( MAX )
=
C IN I OUT ( MAX ) × D ×
Operating Input Voltage Range
VIN(MAX) =
where, IOUT(MAX) is the maximum load current. IRMS has
a maximum value when the input voltage equals twice the
output voltage (VIN = 2 x VOUT), so
IRMS ( MAX ) =
Thermal overload protection limits the total power dissipation in the device. When the junction temperature
exceeds +165°C, an on-chip thermal sensor shuts down
the device, turns off the internal power MOSFETs,
allowing the device to cool down. The thermal sensor
turns the device on after the junction temperature cools
by 10°C.
1 − t OFF(MIN) × f SW
VOUT × (VIN − VOUT )
VIN
=
IRMS I OUT ( MAX ) ×
∆I
< 3.1
2
Thermal Overload Protection
=
VIN(MIN)
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
5.5
f C × VOUT
Maxim Integrated │ 22
MAXM17633/MAXM17634/
MAXM17635
where:
COUT = Output capacitance in μF
VOUT = Output voltage
fC = Desired crossover frequency. fC is chosen to be the
lowest value between 1/10th of the switching frequency
and 80kHz.
Derating of ceramic capacitors with DC-voltage at appropriate AC voltage (equal to the steady-state output
voltage ripple) must be considered while selecting the
output capacitor.
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Setting the Output Voltage
Set the output voltage with a resistive voltage-divider
connected from the output-voltage node (OUT) to SGND
(see Figure 2). Connect the center node of the divider to
the FB pin for MAXM17635. Connect the output-voltage
node (OUT) directly to the FB pin for MAXM17633 and
MAXM17634. Use the following procedure to choose the
resistive voltage-divider values:
Calculate resistor R1 from the output to the FB pin as
follows:
Selection of SS capacitor
The modules implement adjustable soft-start operation to
reduce inrush current. A capacitor connected from the SS pin
to SGND programs the soft-start time. The selected output
capacitance (CSEL) and the output voltage (VOUT) determine
the minimum required soft-start capacitor as follows:
CSS ≥ 28 x 10−6 x CSEL x VOUT
The soft-start time (tSS) is related to the capacitor connected at SS (CSS) by the following equation:
t SS =
C SS
5.55 × 10 −6
For example, to program a 1ms soft-start time, a 5.6nF
capacitor should be connected from the SS pin to SGND.
Note that, during start-up, modules operate at half the
programmed switching frequency until the output voltage
reaches 66.7% of set output nominal voltage.
R1 =
where R1 is in kΩ, crossover frequency fC is in Hz, and
the derated value of the output capacitor COUT is in F.
Calculate resistor R2 connected from the FB pin to SGND
as follows:
R2 =
Choose RU to be 3.3MΩ (max), and then calculate RB
as follows:
RB =
R U × 1.215
(VINU – 1.215)
where VINU is the voltage at which the module is required
to turn on. See Table 1 to set the proper VINU voltage
greater than or equal to the minimum input voltage for
each desired output voltage.
If the EN/UVLO pin is driven from an external signal source,
a series resistance of minimum 1kΩ is recommended to be
placed between the signal source output and and the EN/
UVLO pin, to reduce voltage ringing on the line.
www.maximintegrated.com
R1× 0.9
V
( OUT − 0.9)
R2 is in kΩ.
Select an appropriate fC and COUT so that the parallel
combination of R2 and R1 is less than 50kΩ.
VIN
RU
Setting the Input
Undervoltage-Lockout Level
The modules offer an adjustable input undervoltage lockout level. Set the voltage at which the module turns on with
a resistive voltage-divider connected from IN to GND (see
Figure 1). Connect the center node of the divider to EN/UVLO.
270
f C × C OUT
MAXM17633
MAXM17634
MAXM17635
EN/UVLO
RB
Figure 1. Setting the EN/UVLO Network
VOUT
MAXM17635
R1
FB
R2
Figure 2. Setting the Output Voltage
Maxim Integrated │ 23
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Setting the Switching Frequency (RT)
The switching frequency of the module can be programmed from 400kHz to 2.2MHz by using a resistor
connected from the RT pin to SGND. The switching
frequency (fSW) is related to the resistor (RRT) connected
at the RT pin by the following equation:
R RT ≅
21000
− 1.7
f SW
Where RRT is in kΩ and fSW is in kHz. Leaving the RT pin
open enables the device to operate at the default switching frequency of 500kHz. See Table 1 for RRT resistor
values for a few common switching frequencies.
Power Dissipation
The power dissipation inside the module leads to an
increase in the junction temperature of the modules. The
power loss inside the modules at full load can be estimated as follows:
1
PLOSS= POUT × − 1 ,
η
Where η is the efficiency of the module at the desired operating conditions. See Typical Operating Characteristics
for efficiency, or measure the efficiency to determine total
power dissipation. An EE-SIM model is available for the
MAXM17633/MAXM17634/MAXM17635, to simulate efficiency and power loss. The junction temperature TJ of the
module can be estimated at any given maximum ambient
temperature TA from the following equation:
TJ = TA + [θJA x PLOSS]
For the MAXM17633/MAXM17634/MAXM17635 evaluation board, the thermal resistance from junction to ambient (θJA) is 25°C/W. Operating the module at junction
temperatures greater than +125°C degrades operating
lifetimes.
Table 1. Selection of Components
PART NO.
V INMIN
(V)
V INMAX
(V)
V OUT
(V)
fSW
(kHz)
C IN
C OUT
R1
(kΩ)
R2
(kΩ)
R RT
(kΩ)
MAXM17633
4.5
36
3.3
800
1 x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 47µF 1210 10V
GRM32ER71A476KE15#
SHORT
OPEN
24.3
MAXM17634
7
36
5
1000
1x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 22µF 1210 25V
GRM32ER71E226KE15#
SHORT
OPEN
19.1
4.5
30
0.9
400
2x 4.7µF 1206 50V
GRM31CR71H475KA12#
5 x 47µF 1210 10V
GRM32ER71A476KE15#
39.2
OPEN
51.1
4.5
36
1.2
600
2x 4.7µF 1206 50V
GRM31CR71H475KA12#
2 x 47µF, 10V, 1 x 22µF 25V, 1210
GRM32ER71A476KE15#,
GRM32ER71E226KE15#
51.1
150
33.2
4.5
36
1.5
600
2x 4.7µF 1206 50V
GRM31CR71H475KA12#
2 x 47µF 1210 10V
GRM32ER71A476KE15#
64.9
95.3
33.2
4.5
36
1.8
600
2x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 47µF, 10V, 1 x 22µF 25V, 1210
GRM32ER71A476KE15#
GRM32ER71E226KE15#
86.6
86.6
33.2
4.5
36
2.5
700
1 x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 47µF 1210 10V
GRM32ER71A476KE15#
118
64.9
28.3
4.5
36
3.3
800
1 x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 47µF 1210 10V
GRM32ER71A476KE15#
110
41.2
24.3
7
36
5
1000
1 x 4.7µF 1206 50V
GRM31CR71H475KA12#
1 x 22µF 1210 25V
GRM32ER71E226KE15#
215
46.4
19.1
18
36
12
1800
1 x 2.2µF 1206 50V
C3216X7R1H225K160AE
1 x 10µF 1210 50V
GRM32ER71H106KA12#
453
36.5
10
MAXM17635
www.maximintegrated.com
Maxim Integrated │ 24
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
PCB Layout Guidelines
●● Keep the resistive feedback divider as close as possible to the FB pin.
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation.
●● Connect all of the PGND connections to as large as
copper plane area as possible on the top and bottom
layers.
Use the following guidelines for good PCB layout:
●● Keep the input capacitors as close as possible to the
IN and PGND pins.
●● Use multiple vias to connect internal PGND planes to
the top layer PGND plane.
●● Keep the output capacitors as close as possible to the
OUT and PGND pins.
●● Refer to the MAXM17633/MAXM17634/MAXM17635
EV kit layout for first pass success.
PGND PLANE
C1
LX
C5
IN PLANE
PGND
BST
IN
EXTVCC
R6
EP
C2
EN/
UVLO
RESET
OUT
R4
VCC
SGND
FB
R1
OUT PLANE
R5
RT
MODE/
SYNC
SS
R3
C3
C4
R2
SGND PLANE
Figure 3. Layout Guidelines
www.maximintegrated.com
Maxim Integrated │ 25
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Application Circuits
Typical Application Circuit—Fixed 3.3V Output
VIN
4.5V TO 36V
IN
C1
4.7µF
VOUT
3.3V, 2A
OUT
EN/UVLO
C2
47µF
EXTVCC
VCC
VCC
C3
2.2µF
MODE/SYNC
C4
5600pF
MAXM17633
FB
BST
SS
LX
RT
RESET
R3
24.3kΩ
SGND
C5
0.1µF
VCC
R4
100kΩ
PGND
C1 = MURATA 4.7µF/X7R/50V/1206 (GRM31CR71H475KA12#)
C2 = MURATA 47µF/X7R/10V/1210 (GRM32ER71A476KE15#)
C3 = MURATA 2.2µF/X7R/6.3V/0603 (GRM188R70J225KE15#)
fSW = 800kHz
Typical Application Circuit—Fixed 5V Output
VIN
7V TO 36V
IN
C1
4.7µF
VOUT
5V, 2A
OUT
EN/UVLO
C2
22µF
EXTVCC
VCC
VCC
C3
2.2µF
MODE/SYNC
C4
5600pF
R3
19.1kΩ
MAXM17634
FB
BST
SS
LX
RT
RESET
SGND
C5
0.1µF
VCC
R4
100kΩ
PGND
C1 = MURATA 4.7µF/X7R/50V/1206 (GRM31CR71H475KA12#)
C2 = MURATA 22µF/X7R/25V/1210 (GRM32ER71E226KE15#)
C3 = MURATA 2.2µF/X7R/6.3V/0603 (GRM188R70J225KE15#)
fSW = 1MHz
www.maximintegrated.com
Maxim Integrated │ 26
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Typical Application Circuits (continued)
Typical Application Circuit—Adjustable 2.5V Output
VIN
4.5V TO 36V
IN
C1
4.7µF
VOUT
2.5V, 2A
OUT
EN/UVLO
C2
47µF
EXTVCC
VCC
VCC
C3
2.2µF
MODE/SYNC
C4
5600pF
MAXM17635
FB
BST
SS
LX
RT
RESET
R3
28.3kΩ
SGND
R1
118kΩ
C5
0.1µF
VCC
R2
64.9kΩ
R4
100kΩ
PGND
C1 = MURATA 4.7µF/X7R/50V/1206 (GRM31CR71H475KA12#)
C2 = MURATA 47µF/X7R/10V/1210 (GRM32ER71A476KE15#)
C3 = MURATA 2.2µF/X7R/6.3V/0603 (GRM188R70J225KE15#)
fSW = 700kHz
Typical Application Circuit—Adjustable 12V Output
VIN
18V TO 36V
IN
C1
2.2µF
VOUT
12V, 2A
OUT
EN/UVLO
C2
10µF
EXTVCC
VCC
VCC
C3
2.2µF
MODE/SYNC
C4
5600pF
R3
10kΩ
MAXM17635
FB
BST
SS
LX
RT
RESET
SGND
R1
453kΩ
C5
0.1µF
VCC
R2
36.5kΩ
R4
100kΩ
PGND
C1 = MURATA 4.7µF/X7R/50V/1206 (GRM31CR71H475KA12#)
C2 = MURATA 10µF/X7R/50V/1210 (GRM32ER71H106KA12#)
C3 = MURATA 2.2µF/X7R/6.3V/0603 (GRM188R70J225KE15#)
fSW = 1.8MHz
www.maximintegrated.com
Maxim Integrated │ 27
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Ordering Information
PART NUMBER
TEMP RANGE
PIN-PACKAGE
V OUT
MAXM17633AMG+
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Fixed 3.3V
MAXM17633AMG+T
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Fixed 3.3V
MAXM17634AMG+
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Fixed 5V
MAXM17634AMG+T
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Fixed 5V
MAXM17635AMG+
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Adjustable
MAXM17635AMG+T
-40°C to +125°C
24-pin 4mm x 4mm x 1.75mm uSLIC package
Adjustable
+ Denotes a lead(Pb)-free/RoHS-compliant package.
T= Tape and reel.
www.maximintegrated.com
Maxim Integrated │ 28
MAXM17633/MAXM17634/
MAXM17635
4.5V to 36V, 2A Himalaya uSLIC
Step-Down Power Modules
Revision History
REVISION
NUMBER
REVISION
DATE
0
7/19
DESCRIPTION
Initial release
PAGES
CHANGED
—
For pricing, delivery, and ordering information, please visit Maxim Integrated’s online storefront at https://www.maximintegrated.com/en/storefront/storefront.html.
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.
© 2019 Maxim Integrated Products, Inc. │ 29
工商网监
湘ICP备2023018690号
