19-3872; Rev 0; 3/06
KIT
ATION
EVALU
BLE
AVAILA
2A, 76V, High-Efficiency
MAXPower Step-Down DC-DC Converters
General Description
Features
♦
Wide Input Voltage Range: 6.5V to 76V
♦
Fixed (3.3V, 5V) and Adjustable (1.265V to 11V)
Output-Voltage Versions
♦
2A Output Current
♦
Efficiency Up to 92%
♦
Internal 0.26Ω High-Side DMOS FET
♦
310µA Quiescent Current at No Load
♦
♦
♦
♦
♦
♦
♦
♦
19µA Shutdown Current
Internal Frequency Compensation
Fixed 127kHz Switching Frequency
External Frequency Synchronization
Thermal Shutdown and Short-Circuit Current Limit
-40°C to +125°C Automotive Temperature Range
16-Pin (5mm x 5mm) Thin QFN Package
Capable of Dissipating 2.67W at +70°C
MAX5090A/B/C
The MAX5090A/B/C easy-to-use, high-efficiency, high-
voltage step-down DC-DC converters operate from an
input voltage up to 76V, and consume only 310µA qui-
escent current at no load. This pulse-width-modulated
(PWM) converter operates at a fixed 127kHz switching
frequency at heavy loads, and automatically switches
to pulse-skipping mode to provide low quiescent cur-
rent and high efficiency at light loads. The MAX5090
includes internal frequency compensation simplifying
circuit implementation. The device can also be syn-
chronized with external system clock frequency in a
noise-sensitive application. The MAX5090 uses an
internal low on-resistance and a high-voltage DMOS
transistor to obtain high efficiency and reduce overall
system cost. This device includes undervoltage lock-
out, cycle-by-cycle current limit, hiccup-mode output
short-circuit protection, and overtemperature shutdown.
The MAX5090 delivers up to 2A output current. External
shutdown is included, featuring 19µA (typ) shutdown
current. The MAX5090A/MAX5090B versions have fixed
output voltages of 3.3V and 5V, respectively, while the
MAX5090C features an adjustable 1.265V to 11V output
voltage.
The MAX5090 is available in a space-saving 16-pin thin
QFN package (5mm x 5mm) and operates over the
automotive temperature range (-40°C to +125°C).
Ordering Information
PART
TEMP
RANGE
PIN-
PACKAGE*
OUTPUT
VOLTAGE
(V)
3.3
3.3
5.0
5.0
MAX5090AATE+
-40°C to +125°C 16 TQFN-EP**
MAX5090AATE
-40°C to +125°C 16 TQFN-EP**
Applications
Automotive
Industrial
Distributed Power
MAX5090BATE+
-40°C to +125°C 16 TQFN-EP**
MAX5090BATE
-40°C to +125°C 16 TQFN-EP**
Ordering Information continued at end of data sheet.
*The
package code is T1655-3.
**EP
= Exposed pad.
+Denotes
lead-free package.
Typical Operating Circuit
PGND
N.C.
Pin Configuration
SGND
10
TOP VIEW
VIN
7.5V TO 76V
R
IN
10Ω
C
BYPASS
0.47µF
V
IN
ON/OFF
BST
FB
SYNC
SGND
PGND
SS
VD
3.3µF
C
SS
0.047µF
DRAIN
LX
C
BST
0.22µF
D1
PDS5100H
C
OUT
100µF
100µH
V
OUT
5V/2A
12
11
ON/OFF
9
C
IN
68µF
DRAIN 13
DRAIN 14
N.C. 15
N.C. 16
EP
8
7
FB
SS
SYNC
VD
MA5090
6
5
MAX5090B
1
LX
2
LX
3
BST
4
V
IN
TQFN
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
2A, 76V, High-Efficiency MAXPower Step-Down
DC-DC Converters
MAX5090A/B/C
ABSOLUTE MAXIMUM RATINGS
(Voltages referenced to PGND, unless otherwise specified.)
V
IN
, DRAIN .............................................................-0.3V to +80V
SGND, PGND.………………………………………-0.3V to +0.3V
LX.................................................................-0.8V to (V
IN
+ 0.3V)
BST ...............................................................-0.3V to (V
IN
+ 10V)
BST to LX................................................................-0.3V to +10V
ON/OFF........................................................-0.3V
to (V
IN
+ 0.3V)
VD, SYNC ...............................................................-0.3V to +12V
SS…………………………………………………………-0.3 to +4V
FB
MAX5090A/MAX5090B…………….……… ...….-0.3V to +15V
MAX5090C ................1mA (internally clamped to +2V, -0.3V)
*As
per JEDEC 51 Standard Multilayer Board.
Stresses beyond those listed under "Absolute Maximum Ratings" may cause 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 maxi-
mum rating conditions for extended periods may affect device reliability.
V
OUT
Short-Circuit Duration………………………… ...Continuous
VD Short-Circuit Duration………….............................Continuous
Continuous Power Dissipation (T
A
= +70°C)*
16-Pin TQFN (derate 33.3mW/°C above +70°C) ........2.667W
Operating Junction Temperature Range ...........-40°C to +125°C
Storage Temperature Range .........................…-65°C to +150°C
Junction Temperature……...……………………………….+150°C
Lead Temperature (soldering, 10s) .................................+300°C
ELECTRICAL CHARACTERISTICS
(V
IN
= +12V, V
ON/OFF
= +12V, V
SYNC
= 0V, I
OUT
= 0, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at
T
A
= +25°C. See the
Typical Operating Circuit.)
(Note 1)
PARAMETER
Input Voltage Range
Undervoltage Lockout
UVLO Hysteresis
Output Voltage
Output Voltage Range
Feedback Voltage
Efficiency
SYMBOL
V
IN
UVLO
UVLO
HYS
MAX5090A
V
OUT
V
OUT
V
FB
η
MAX5090B
MAX5090B
V
IN
= 6.5V to 76V, I
OUT
= 0 to 2A
V
IN
= 7.5V to 76V, I
OUT
= 0 to 2A
V
IN
= 7V to 76V, I
OUT
= 0 to 1A
3.20
4.85
4.85
1.265
1.191
1.228
80
88
88
310
310
310
310
310
310
310
310
310
19
550
550
550
570
570
570
650
650
650
45
µA
µA
µA
µA
%
V
IN
rising
CONDITIONS
MIN
6.5
5.70
6.17
0.5
3.3
5.0
5.0
3.39
5.15
5.15
11.000
1.265
V
V
V
TYP
MAX
76.0
6.45
UNITS
V
V
V
MAX5090C only
MAX5090C, V
IN
= 6.5V to 76V
MAX5090A
MAX5090B
MAX5090C
MAX5090A
V
IN
= 12V, I
OUT
= 1A
V
IN
= 12V, I
OUT
= 1A
V
IN
= 12V, V
OUT
= 5V, I
OUT
= 1A
V
IN
= 6.5V to 28V
V
IN
= 7V to 28V
V
IN
= 6.5V to 28V
V
IN
= 6.5V to 40V
V
IN
= 7V to 40V
V
IN
= 6.5V to 40V
V
IN
= 6.5V to 76V
V
IN
= 7V to 76V
V
IN
= 6.5V to 76V
Quiescent Supply Current
(Note 2)
I
Q
MAX5090B
MAX5090C
MAX5090A
Quiescent Supply Current
(Note 2)
I
Q
MAX5090B
MAX5090C
MAX5090A
Quiescent Supply Current
(Note 2)
Shutdown Current
SOFT-START
Default Internal Soft-Start
Period
Soft-Start Charge Current
I
Q
I
SHDN
MAX5090B
MAX5090C
V
ON/OFF
= 0V, V
IN
= 14V
C
SS
= 0
I
SS
4.5
700
10
16.0
µs
µA
2
_______________________________________________________________________________________
2A, 76V, High-Efficiency MAXPower Step-Down
DC-DC Converters
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V, V
ON/OFF
= +12V, V
SYNC
= 0V, I
OUT
= 0, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at
T
A
= +25°C. See the
Typical Operating Circuit.)
(Note 1)
PARAMETER
Soft-Start Reference Voltage
Peak Switch Current Limit
Switch Leakage Current
Switch On-Resistance
PFM Threshold
PFM Threshold
FB Input Bias Current
ON/OFF CONTROL INPUT
ON/OFF Input-Voltage
Threshold
ON/OFF Input-Voltage
Hysteresis
ON/OFF Input Current
Oscillator Frequency
Synchronization
Maximum Duty Cycle
SYNC High-Level Voltage
SYNC Low-Level Voltage
SYNC Minimum Pulse Width
SYNC Input Leakage
INTERNAL VOLTAGE REGULATOR
Regulator Output Voltage
Dropout Voltage
Load Regulation
∆VD/∆I
VD
VD
V
IN
= 9V to 76V, I
OUT
= 0
6.5V
≤
V
IN
≤
8.5V, I
OUT
= 15mA
0 to 15mA
7.0
7.8
0.5
10
8.4
V
V
Ω
-1
V
ON/OFF
V
HYST
I
ON/OFF
f
0SC
f
SYNC
D
MAX
V
IN
= 6.5V to 76V, V
OUT
≤
11V
V
ON/OFF
= 0V to V
IN
106
119
80
2.0
0.8
350
+1
95
Rising trip point
1.180
1.38
100
10
127
100
150
200
1.546
V
mV
nA
kHz
kHz
%
V
V
ns
µA
SYMBOL
V
SS(REF)
I
LIM
I
OL
R
DS(ON)
I
PFM
I
PFM
I
B
(Note 3)
V
IN
= 76V, V
ON/OFF
= 0V, V
LX
= 0V
I
SWITCH
= 1A
Minimum switch current in any cycle
Minimum switch current in any cycle at T
J
≤
+25°C
(Note 4)
MAX5090C, V
FB
= 1.2V
1
14
-150
+0.1
CONDITIONS
MIN
1.23
2.4
-10
0.26
60
TYP
1.46
3.3
MAX
1.65
5.0
+10
0.4
300
300
+150
UNITS
V
A
µA
Ω
mA
mA
nA
MAX5090A/B/C
INTERNAL SWITCH/CURRENT LIMIT
OSCILLATOR/SYNCHRONIZATION
PACKAGE THERMAL CHARACTERISTICS
Thermal Resistance
(Junction to Ambient)
THERMAL SHUTDOWN
Thermal-Shutdown Junction
Temperature
Thermal-Shutdown
Hysteresis
T
SH
T
HYST
Temperature rising
+175
20
°C
°C
θ
JA
TQFN package (JEDEC 51)
30
°C/W
Note 1:
All limits at -40°C are guaranteed by design, not production tested.
Note 2:
For total current consumption during switching (at no load), also see the
Typical Operating Characteristics.
Note 3:
Switch current at which the current-limit circuit is activated.
Note 4:
Limits are guaranteed by design.
_______________________________________________________________________________________
3
2A, 76V, High-Efficiency MAXPower Step-Down
DC-DC Converters
MAX5090A/B/C
Typical Operating Characteristics
(V
IN
= 12V, V
ON/OFF
=12V, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. See the
Typical
Operating Circuit,
if applicable.)
V
OUT
vs. TEMPERATURE
(MAX5090AATE, V
OUT
= 3.3V)
MAX5090 toc01
V
OUT
vs. TEMPERATURE
(MAX5090BATE, V
OUT
= 5V)
MAX5090 toc02
LINE REGULATION
(MAX5090AATE, V
OUT
= 3.3V)
3.38
3.36
3.34
I
OUT
= 0
MAX5090 toc03
3.40
3.38
3.36
3.34
V
OUT
(V)
5.15
5.10
5.05
V
OUT
(V)
3.40
3.30
3.28
3.26
3.24
3.22
3.20
-50
-25
0
25
50
75
100 125 150
AMBIENT TEMPERATURE (°C)
I
OUT
= 2A
5.00
4.95
4.90
4.85
-50
-25
0
25
50
75
100 125 150
AMBIENT TEMPERATURE (°C)
I
OUT
= 2A
V
OUT
(V)
3.32
I
OUT
= 0
I
OUT
= 0
3.32
3.30
3.28
3.26
3.24
3.22
3.20
6.5
16
26
I
OUT
= 2A
36
46
56
66
76
V
IN
(V)
LINE REGULATION
(MAX5090BATE, V
OUT
= 5V)
MAX5090 toc04
LOAD REGULATION
(MAX5090AATE, V
OUT
= 3.3V)
MAX5090 toc05
LOAD REGULATION
(MAX5090BATE, V
OUT
= 5V)
MAX5090 toc06
5.15
5.10
5.05
V
OUT
(V)
5.00
4.95
4.90
4.85
6.5
16
26
36
46
56
66
I
OUT
= 0
3.40
3.38
3.36
3.34
V
OUT
(V)
V
IN
= 76V
5.15
5.10
5.05
V
OUT
(V)
5.00
4.95
4.90
4.85
V
IN
= 6.5V
V
IN
= 24V
V
IN
= 76V
3.32
3.30
3.28
I
OUT
= 2A
3.26
3.24
3.22
3.20
76
0.1
V
IN
= 6.5V
V
IN
= 24V
1
10
100
I
LOAD
(mA)
1000
10,000
0.1
1
10
100
I
LOAD
(mA)
1000
10,000
V
IN
(V)
EFFICIENCY vs. LOAD CURRENT
(MAX5090AATE, VOUT = 3.3V)
MAX5090 toc07
EFFICIENCY vs. LOAD CURRENT
(MAX5090BATE, V
OUT
= 5V)
MAX5090 toc08
OUTPUT CURRENT LIMIT vs. TEMPERATURE
(MAX5090AATE)
V
OUT
= 3.3V
5% DROP IN V
OUT
PULSED OUTPUT LOAD
MAX5090 toc09
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
0
400
800
1200
1600
V
IN
= 6.5V
V
IN
= 12V
V
IN
= 24V
V
IN
= 48V
V
IN
= 76V
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
0
V
IN
= 76V
V
IN
= 6.5V
V
IN
= 12V
V
IN
= 24V
V
IN
= 48V
4.0
3.5
3.0
2.5
2.0
1.5
1.0
OUTPUT CURRENT LIMIT (A)
2000
0
400
800
1200
1600
2000
-50
-25
0
25
50
75
100 125 150
LOAD CURRENT (mA)
LOAD CURRENT (mA)
AMBIENT TEMPERATURE (°C)
4
_______________________________________________________________________________________
2A, 76V, High-Efficiency MAXPower Step-Down
DC-DC Converters
MAX5090A/B/C
Typical Operating Characteristics (continued)
(V
IN
= 12V, V
ON/OFF
=12V, T
A
= T
J
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
= +25°C. See the
Typical
Operating Circuit,
if applicable.)
OUTPUT CURRENT LIMIT vs. TEMPERATURE
(MAX5090BATE)
MAX5090 toc010
OUTPUT CURRENT LIMIT vs. INPUT VOLTAGE
(MAX5090AATE)
V
OUT
= 3.3V
5% DROP IN V
OUT
PULSED OUTPUT LOAD
MAX5090 toc11
OUTPUT CURRENT LIMIT vs. INPUT VOLTAGE
(MAX5090BATE)
V
OUT
= 5V
5% DROP IN V
OUT
PULSED OUTPUT LOAD
MAX5090 toc12
4.0
3.5
3.0
2.5
2.0
1.5
1.0
OUTPUT CURRENT LIMIT (A)
OUTPUT CURRENT LIMIT (A)
OUTPUT CURRENT LIMIT (A)
V
OUT
= 5V
5% DROP IN V
OUT
PULSED OUTPUT LOAD
7.0
6.0
5.0
4.0
3.0
2.0
1.0
7.0
6.0
5.0
4.0
3.0
2.0
1.0
-50
-25
0
25
50
75
100 125 150
6.5
16
26
36
46
56
66
76
6.5
16
26
36
46
56
66
76
AMBIENT TEMPERATURE (°C)
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
NO-LOAD SUPPLY CURRENT vs. TEMPERATURE
(MAX5090AATE)
MAX5090 toc13
NO-LOAD SUPPLY CURRENT vs. INPUT VOLTAGE
(MAX5090AATE)
MAX5090 toc14
SHUTDOWN CURRENT vs. TEMPERATURE
(MAX5090AATE)
V
OUT
= 3.3V
SHUTDOWN CURRENT (µA)
26
MAX5090 toc15
600
V
OUT
= 3.3V
NO-LOAD SUPPLY CURRENT (µA)
550
500
450
400
350
300
-50
-25
0
25
50
75
600
V
OUT
= 3.3V
NO-LOAD SUPPLY CURRENT
550
500
450
400
350
300
30
22
18
14
10
6.5
16
26
36
46
56
66
76
-50
-25
0
25
50
100 125 150 175
INPUT VOLTAGE (V)
AMBIENT TEMPERATURE (°C)
100 125 150
AMBIENT TEMPERATURE (°C)
SHUTDOWN CURRENT
vs. INPUT VOLTAGE
MAX5090 toc16
OUTPUT VOLTAGE
vs. INPUT VOLTAGE
MAX5090 toc17
LOAD-TRANSIENT RESPONSE
(MAX5090AATE)
MAX5090 toc18
45
40
SHUTDOWN CURRENT (µA)
35
30
25
20
15
10
5
0
6.5
16
26
36
46
56
66
76
INPUT VOLTAGE (V)
V
OUT
= 3.3V
13
MAX5090CATE
V
OUT
= 11V
V
ON/OFF
= V
IN
V
OUT
= 3.3V
A
11
V
OUT
(V)
9
I
OUT
= 2A
6
I
OUT
= 1A
I
OUT
= 0A
B
3
0
5
6
7
8
9
10 11 11.5 12 12.5 13
V
IN
(V)
400µs/div
A: V
OUT
, 200mV/div, AC-COUPLED
B: I
OUT
, 1A/div, 1A TO 2A
_______________________________________________________________________________________
5
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