19-2590; Rev 1; 11/03
IT
TION K
VALUA
E
BLE
AVAILA
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
General Description
The MAX5052/MAX5053 current-mode PWM controllers
contain all the control circuitry required for the design of
wide-input-voltage isolated and nonisolated power
supplies. The MAX5052 is well suited for universal input
(rectified 85VAC to 265VAC) or telecom (-36VDC to
-72VDC) power supplies. The MAX5053 is well suited for
low-input-voltage (10.8VDC to 24VDC) power supplies.
The MAX5052/MAX5053 contain an internal error ampli-
fier that regulates the tertiary winding output voltage.
This implements a primary-side regulated, isolated
power supply, eliminating the need for an optocoupler.
An input undervoltage lockout (UVLO) is provided for
programming the input-supply start voltage and to
ensure proper operation during brownout conditions.
The input-supply start voltage is externally programma-
ble with a voltage-divider. To shutdown the device, the
UVLO pin is pulled low. Internal digital soft-start
reduces output voltage overshoot. The internal thermal
shutdown circuit protects the device in the event the
junction temperature exceeds +130°C.
The MAX5052 has an internal bootstrap UVLO with
large hysteresis that requires a minimum voltage of
23.6V for startup. The MAX5053 does not have the
internal bootstrap UVLO and can be biased directly
from a minimum voltage of 10.8V.
The 262kHz switching frequency is internally trimmed to
±12% accuracy; this allows the optimization of the
magnetic and filter components resulting in compact,
cost-effective power supplies. The MAX5052A/
MAX5053A are offered with a 50% maximum duty-cycle
limit. The MAX5052B/MAX5053B are offered with a 75%
maximum duty-cycle limit. These devices are available
in 8-pin µMAX packages and operate over the -40°C to
+85°C temperature range.
♦
Current-Mode Control
♦
50W Output Power
♦
Universal Offline Input Voltage Range
Rectified 85VAC to 265VAC (MAX5052)
♦
V
IN
Directly Driven from 10.8V to 24V Input
(MAX5053)
♦
Digital Soft-Start
♦
Programmable Input Startup Voltage
♦
Internal Bootstrap UVLO with Large Hysteresis
(MAX5052)
♦
Internal Error Amplifier with 1% Accurate
Reference
♦
Thermal Shutdown
♦
45µA (typ) Startup Supply Current
♦
1.4mA (typ) Operating Supply Current
♦
Fixed Switching Frequency of 262kHz ±12%
♦
50% Maximum Duty-Cycle Limit
(MAX5052A/MAX5053A)
♦
75% Maximum Duty-Cycle Limit
(MAX5052B/MAX5053B)
♦
60ns Cycle-by-Cycle Current-Limit Response Time
Features
♦
Available in a Tiny 8-Pin µMAX Package
MAX5052/MAX5053
Ordering Information
PART
MAX5052AEUA
MAX5052BEUA
MAX5053AEUA
MAX5053BEUA
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
8 µMAX
8 µMAX
8 µMAX
8 µMAX
Applications
Universal Input AC
Power Supplies
Isolated Telecom Power
Supplies
Networking Systems
Computer Systems/
Servers
Industrial Power
Conversion
Isolated Keep-Alive
Circuits
12V Boost Regulators
12V SEPIC Regulators
Warning:
The MAX5052/MAX5053 are designed to work with
high voltages. Exercise caution.
Pin Configuration
TOP VIEW
UVLO/EN
1
FB
2
COMP
3
8
7
V
IN
V
CC
NDRV
GND
MAX5052
MAX5053
6
5
CS
4
Functional Diagram/Typical Operating Circuit/Selector
Guide appear at end of data sheet.
µMAX
1
________________________________________________________________
Maxim Integrated Products
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.
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
MAX5052/MAX5053
ABSOLUTE MAXIMUM RATINGS
V
IN
to GND .............................................................-0.3V to +30V
V
CC
to GND ............................................................-0.3V to +13V
FB, COMP, UVLO, CS to GND .................................-0.3V to +6V
NDRV to GND.............................................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) ..............362mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range ............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°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.
ELECTRICAL CHARACTERISTICS
(V
IN
= +12V (for MAX5052, V
IN
must first be brought up to 23.6V for startup), 10nF bypass capacitors at V
IN
and V
CC
, C
NDRV
= 0,
V
UVLO
= +1.4V, V
FB
= +1.0V, V
COMP
= floating, V
CS
= 0V, typical values are measured at T
A
= +25°C, T
A
= -40°C to + 85°C, unless
otherwise noted.) (Note 1)
PARAMETER
Bootstrap UVLO Wake-Up Level
Bootstrap UVLO Shutdown Level
UVLO/EN Wake-Up Threshold
UVLO/EN Shutdown Threshold
UVLO/EN Input Current
UVLO/EN Hysteresis
V
IN
Supply Current In
Undervoltage Lockout
V
IN
Range
UVLO/EN Propagation Delay
Bootstrap UVLO Propagation
Delay
INTERNAL SUPPLY
V
CC
Regulator Set Point
V
IN
Supply Current After Startup
Shutdown Supply Current
GATE DRIVER
Driver Output Impedance
Driver Peak Sink Current
Driver Peak Source Current
PWM COMPARATOR
Comparator Offset Voltage
CS Input Bias Current
Comparator Propagation Delay
Minimum On-Time
VO
PWM
I
CS
t
PWM
t
ON(MIN)
V
COMP
- V
CS
V
CS
= 0V
V
CS
= +0.1V
1.15
-2
60
150
1.38
1.70
+2
V
µA
ns
ns
R
ON(LOW)
Measured at NDRV sinking, 100mA
2
4
1
0.65
4
12
R
ON(HIGH)
Measured at NDRV sourcing, 20mA
Ω
A
A
V
CCSP
I
IN
V
IN
= +10.8V to +24V, sinking 1µA to 20mA
from V
CC
V
IN
= +24V
UVLO/EN = low
7
1.4
10.5
2.5
90
V
mA
µA
I
START
V
IN
t
EXTR
t
EXTF
t
BUVR
t
BUVF
UVLO/EN steps up from +1.1V to +1.4V
UVLO/EN steps down from +1.4V to +1.1V
V
IN
steps up from +9V to +24V
V
IN
steps down from +24V to +9V
V
IN
= +19V, for MAX5052 only when in
bootstrap UVLO
10.8
12
1.8
5
1
SYMBOL
V
SUVR
V
SUVF
V
ULR2
V
ULF2
I
UVLO
CONDITIONS
V
IN
rising (MAX5052 only)
V
IN
falling (MAX5052 only)
UVLO/EN rising
UVLO/EN falling
T
J
= +125°C
MIN
19.68
9.05
1.188
1.168
TYP
21.6
9.74
1.28
1.23
25
50
45
90
24
MAX
23.60
10.43
1.371
1.291
UNITS
V
V
V
V
nA
mV
µA
V
µs
µs
UNDERVOLTAGE LOCKOUT/STARTUP
2
_______________________________________________________________________________________
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V (for MAX5052, V
IN
must first be brought up to 23.6V for startup), 10nF bypass capacitors at V
IN
and V
CC
, C
NDRV
= 0,
V
UVLO
= +1.4V, V
FB
= +1.0V, V
COMP
= floating, V
CS
= 0V, typical values are measured at T
A
= +25°C, T
A
= -40°C to + 85°C, unless
otherwise noted.) (Note 1)
PARAMETER
CURRENT-LIMIT COMPARATOR
Current-Limit Trip Threshold
CS Input Bias Current
Propagation Delay From
Comparator Input to NDRV
Switching Frequency
Maximum Duty Cycle
V
IN
CLAMP VOLTAGE
V
IN
Clamp Voltage
ERROR AMPLIFIER
Voltage Gain
Unity-Gain Bandwidth
Phase Margin
FB Input Offset Voltage
COMP Pin Clamp Voltage
Source Current
Sink Current
Reference Voltage
Input Bias Current
COMP Short-Circuit Current
THERMAL SHUTDOWN
Thermal-Shutdown Temperature
Thermal Hysteresis
DIGITAL SOFT-START
Soft-Start Duration
Reference Voltage Steps During
Soft-Start
Reference Voltage Step
15,872
31
40
clock
cycles
steps
mV
130
25
°C
°C
8
V
REF
(Note 2)
High
Low
2.2
0.4
0.5
0.5
1.218
1.230
1.242
50
R
LOAD
= 100kΩ
R
LOAD
= 100kΩ, C
LOAD
= 200pF
R
LOAD
= 100kΩ, C
LOAD
= 200pF
80
2
65
3
3.5
1.1
dB
MHz
degrees
mV
V
mA
mA
V
nA
mA
V
INC
2mA sink current, MAX5052 only (Note 3)
24.1
26.1
29.0
V
V
CS
I
CS
t
PWM
f
SW
D
MAX
MAX505_A
MAX505_B
V
CS
= 0V
50mV overdrive
230
262
-2
60
262
50
75
290
50.5
76
291
320
+2
mV
µA
ns
kHz
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5052/MAX5053
Note 1:
All devices are 100% tested at T
A
= +85°C. All limits over temperature are guaranteed by characterization.
Note 2:
V
REF
is measured with FB connected to the COMP pin (see
Functional Diagram).
Note 3:
The MAX5052 is intended for use in universal input power supplies. The internal clamp circuit is used to prevent the boot-
strap capacitor (C1 in Figure 1) from charging to a voltage beyond the absolute maximum rating of the device when
EN/UVLO is low. The maximum current to V
IN
(hence to clamp) when UVLO is low (device in shutdown) must be externally
limited to 2mA, max. Clamp currents higher than 2mA may result in clamp voltage higher than 30V, thus exceeding the
absolute maximum rating for V
IN
. For the MAX5053, do not exceed the 24V maximum operating voltage of the device.
_______________________________________________________________________________________
3
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
MAX5052/MAX5053
Typical Operating Characteristics
(UVLO = +1.4V, V
FB
= +1V, V
COMP
= floating, V
CS
= 0V, T
A
= +25°C, unless otherwise noted.)
BOOTSTRAP UVLO WAKE-UP LEVEL
vs. TEMPERATURE
MAX5052 toc01
BOOTSTRAP UVLO SHUTDOWN LEVEL
vs. TEMPERATURE
MAX5052 V
IN
FALLING
10.0
UVLO/EN (V)
MAX5052 toc02
UVLO/EN WAKE-UP THRESHOLD
vs. TEMPERATURE
UVLO/EN RISING
1.275
1.270
1.265
1.260
MAX5052 toc03
MAX5052 toc09
MAX5052 toc06
21.60
MAX5052 V
IN
RISING
21.55
21.50
V
IN
(V)
21.45
21.40
10.1
1.280
V
IN
(V)
9.9
9.8
21.35
21.30
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
9.7
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
1.255
1.250
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
UVLO/EN SHUTDOWN THRESHOLD
vs. TEMPERATURE
MAX5052 toc04
V
IN
SUPPLY CURRENT IN UNDERVOLTAGE
LOCKOUT vs. TEMPERATURE
MAX5052 toc05
V
IN
SUPPLY CURRENT AFTER STARTUP
vs. TEMPERATURE
1.5
V
IN
= 24V
1.4
I
IN
(mA)
1.30
UVLO/EN FALLING
52
51
50
49
V
IN
= 19V
MAX5052 WHEN IN BOOTSTRAP UVLO
MAX5053 WHEN UVLO/EN IS LOW
1.25
UVLO/EN (V)
I
START
(µA)
48
47
46
45
44
43
1.20
1.3
1.15
1.2
1.10
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
42
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
1.1
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
V
CC
REGULATOR SET POINT
vs. TEMPERATURE
MAX5052 toc07
V
CC
REGULATOR SET POINT
vs. TEMPERATURE
MAX5052 toc08
CURRENT-LIMIT TRIP THRESHOLD
vs. TEMPERATURE
310
CURRENT-LIMIT TRIP THRESHOLD (mV)
305
300
295
290
285
280
275
270
-40
-20
0
20
40
60
80
-3σ
MEAN
+3σ
TOTAL NUMBER OF
DEVICES = 100
9.8
9.7
9.6
V
CC
(V)
9.5
9.4
9.3
9.2
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
NDRV OUTPUT IS
SWITCHING
V
IN
= 19V
NO LOAD
NDRV OUTPUT IS NOT
SWITCHING, V
FB
= 1.5V
8.9
V
IN
= 10.8V
8.8
8.7
10mA LOAD
8.6
V
CC
(V)
8.5
8.4
20mA LOAD
8.3
8.2
8.1
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Current-Mode PWM Controllers with an Error
Amplifier for Isolated/Nonisolated Power Supplies
MAX5052/MAX5053
Typical Operating Characteristics (continued)
(UVLO = +1.4V, V
FB
= +1V, V
COMP
= floating, V
CS
= 0V, T
A
= +25°C, unless otherwise noted.)
SWITCHING FREQUENCY
vs. TEMPERATURE
MAX5052 toc11
MAX5052 toc10
CURRENT-LIMIT TRIP THRESHOLD
30
25
PERCENTAGE OF UNITS (%)
20
15
10
5
0
260
270
280
290
300
310
320
CURRENT-LIMIT TRIP THRESHOLD (mV)
280
275
SWITCHING FREQUENCY (kHz)
270
265
260
255
250
245
240
-40
-3σ
MEAN
+3σ
TOTAL NUMBER OF
DEVICES = 200
SWITCHING FREQUENCY
TOTAL NUMBER OF
DEVICES = 200
MAX5052 toc12
MAX5052 toc18
MAX5052 toc15
TOTAL NUMBER OF
DEVICES = 100
30
25
PERCENTAGE OF UNITS (%)
20
15
10
5
0
-20
0
20
40
60
80
230
240
250
260
270
280
290
TEMPERATURE (°C)
SWITCHING FREQUENCY (kHz)
PROPAGATION DELAY FROM CURRENT-LIMIT
COMPARATOR INPUT TO NDRV vs. TEMPERATURE
MAX5052 toc13
UVLO/EN PROPAGATION DELAY
vs. TEMPERATURE
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
-40
-20
0
20
MAX5052 toc14
REFERENCE VOLTAGE
vs. TEMPERATURE
1.230
V
IN
= 12V
75
UNDERVOLTAGE LOCKOUT DELAY (µs)
UVLO/EN RISING
REFERENCE VOLTAGE (V)
UVLO/EN FALLING
70
1.229
t
PWM
(ns)
65
1.228
60
1.227
55
1.226
50
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
1.225
40
60
80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
INPUT CURRENT
vs. INPUT CLAMP VOLTAGE
MAX5052 toc16
INPUT CLAMP VOLTAGE
vs. TEMPERATURE
26.8
INPUT CLAMP VOLTAGE (V)
26.6
26.4
R
ON
(Ω)
26.2
26.0
25.8
25.6
25.4
25.2
25.0
I
IN
= 2mA
MAX5052 toc17
NDRV OUTPUT IMPEDANCE
vs. TEMPERATURE
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
V
IN
= 24V
SINKING 100mA
10
9
8
INPUT CURRENT (mA)
7
6
5
4
3
2
1
0
27.0
10.0 12.5 15.0 17.5 20.0 22.5 25.0 27.5 30.0
INPUT VOLTAGE (V)
-40
-20
0
20
40
60
80
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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