19-5485; Rev 1; 7/11
KIT
ATION
EVALU
BLE
AVAILA
Current-Mode PWM Controllers with
Programmable Switching Frequency
Features
o
Current-Mode Control
o
Programmable Switching Frequency Up to 625kHz
o
Accurate UVLO Threshold (1%)
o
Open-Drain UVLO Flag Output with Internal Delay
o
36V to 72V Telecom Voltage Range
o
Universal Offline Input Voltage Range
Rectified 85V AC to 265V AC (MAX17500)
o
9.5V to 24V Input (MAX17499)
o
Digital Soft-Start
o
Internal Bootstrap UVLO with Large Hysteresis
(MAX17500)
o
Internal Error Amplifier with 1.5% Accurate
Reference
o
50µA (typ) Startup Supply Current
o
50% Maximum Duty-Cycle Limit
(MAX17499A/MAX17500A)
o
75% Maximum Duty-Cycle Limit
(MAX17499B/MAX17500B)
o
60ns Cycle-by-Cycle Current-Limit Propagation
Delay
o
Available in Tiny 10-Pin
µMAX
Packages
General Description
The MAX17499/MAX17500 current-mode PWM con-
trollers contain all the control circuitry required for the
design of wide-input-voltage isolated and nonisolated
power supplies. The MAX17499 is well suited for low
input voltage (9.5V DC to 24V DC) power supplies. The
MAX17500 is well suited for universal input (rectified
85V AC to 265V AC) or telecom (-36V DC to -72V DC)
power supplies.
The ICs contain an internal error amplifier that regulates
the tertiary winding output voltage that is used in prima-
ry-side-regulated isolated power supplies. Primary-side
regulation eliminates the need for an optocoupler. An
input undervoltage lockout (UVLO) is provided for pro-
gramming the input-supply start voltage and to ensure
proper operation during brownout conditions. An open-
drain UVLO flag output, with 210μs internal delay,
allows the sequencing of a secondary-side controller.
The input-supply start voltage is externally programma-
ble with a voltage-divider. A UVLO/EN input is used to
shut down the devices. Internal digital soft-start elimi-
nates output voltage overshoot.
The MAX17500 has an internal bootstrap UVLO with
large hysteresis that requires a minimum 23.6V for start-
up. The MAX17499 does not have the internal bootstrap
UVLO and can be biased directly from a minimum volt-
age of 9.5V.
The switching frequency for the ICs is programmable
with an external resistor. The MAX17499A/MAX17500A
provide a 50% maximum duty-cycle limit, while the
MAX17499B/MAX17500B provide a 75% maximum
duty-cycle limit. These devices are available in 10-pin
μMAX
®
packages and are rated for operation over the
-40°C to +125°C temperature range.
MAX17499/MAX17500
Applications
1/2, 1/4, and 1/8 Brick Power Modules
High-Efficiency, Isolated Telecom Power
Supplies
Networking/Servers
Isolated Keep-Alive Power Supplies
12V Boost and SEPIC Regulators
Isolated and Nonisolated High-Brightness LED
Power Supplies
Industrial Power Conversion
Selector Guide appears at end of data sheet.
μMAX is a registered trademark of Maxim Integrated Products, Inc.
Ordering Information
PART
MAX17499AAUB+
MAX17499BAUB+
MAX17500AAUB+
MAX17500BAUB+
D
MAX
(%)
50
75
50
75
STARTUP VOLTAGE (V)
9.5
9.5
22
22
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
10 μMAX
10 μMAX
10 μMAX
10 μMAX
Warning:
The ICs are designed to work with high voltages. Exercise caution.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Current-Mode PWM Controllers with
Programmable Switching Frequency
MAX17499/MAX17500
ABSOLUTE MAXIMUM RATINGS
IN to GND ...............................................................-0.3V to +30V
IN Clamp (internal shunt) Current .........................................5mA
V
CC
to GND ............................................................-0.3V to +13V
FB, COMP, UVLO/EN, RT, CS to GND .....................-0.3V to +6V
UFLG to GND .........................................................-0.3V to +30V
NDRV to GND.............................................-0.3V to (V
CC
+ 0.3V)
Continuous Power Dissipation (T
A
= +70°C)
10-Pin μMAX (derate 5.6mW/°C above +70°C) ........444.4mW
Operating 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
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.
ELECTRICAL CHARACTERISTICS
(V
IN
= +12V (for MAX17500, bring V
IN
up to 23.6V for startup), 10nF bypass capacitors at IN and V
CC
, R12 = 15kΩ (MAX17499A/
MAX17500A), R12 = 7.5kΩ (MAX17499B/MAX17500B), R15 = 1kΩ, C6 = 100nF (see the
Typical Application Circuit),
NDRV = open,
V
UVLO/EN
= +1.4V, V
FB
= +1.0V, COMP = open, V
CS
= 0V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
UVLO/STARTUP
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
IN Supply Current In UVLO
IN Input Voltage Range
UVLO/EN to UFLG Propagation
Delay (Figure 3)
UVLO/EN to NDRV Propagation
Delay (Figure 3)
t
EXTR
t
EXTF
t
BUVR
t
BUVF
UFLG Low Output Voltage
UFLG High Output Leakage
Current
INTERNAL SUPPLY
V
CC
Regulator Set Point
IN Supply Current After Startup
Shutdown Supply Current
V
CCSP
I
IN
V
IN
= 10.8V to 24V, sinking 1μA to 20mA
from V
CC
V
IN
= 24V
UVLO/EN = low
7.0
2
50
10.5
4
90
V
mA
μA
V
UFLG
I
START
V
IN
V
IN
= 19V, MAX17500 only when in
bootstrap UVLO
MAX17499 only
UVLO/EN steps up from 1V to 1.4V
UVLO/EN steps down from 1.4V to 1V
UVLO/EN steps up from 1V to 1.4V
UVLO/EN steps down from 1.4V to 1V
V
IN
steps up from 9V to 24V (MAX17500
only)
V
IN
steps down from 24V to 9V
(MAX17500 only)
I
UFLG
= 5mA sinking
V
UFLG
= 25V
0.1
150
9.5
3
0.6
3
210
5
μs
1
1.5
1
V
μA
10
300
V
SUVR
V
SUVF
V
ULR2
V
ULF2
I
UVLO
V
IN
rising (MAX17500 only)
V
IN
falling (MAX17500 only)
UVLO/EN rising
UVLO/EN falling
V
UVLO/EN
≤
2V
19.68
9.05
1.215
1.14
-50
60
50
90
24.0
21.6
9.74
1.23
1.17
23.60
10.43
1.245
1.20
+50
V
V
V
V
nA
mV
μA
V
μs
ms
μs
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Bootstrap UVLO Propagation
Delay
2
_______________________________________________________________________________________
Current-Mode PWM Controllers with
Programmable Switching Frequency
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V (for MAX17500, bring V
IN
up to 23.6V for startup), 10nF bypass capacitors at IN and V
CC
, R12 = 15kΩ (MAX17499A/
MAX17500A), R12 = 7.5kΩ (MAX17499B/MAX17500B), R15 = 1kΩ, C6 = 100nF (see the
Typical Application Circuit),
NDRV = open,
V
UVLO/EN
= +1.4V, V
FB
= +1.0V, COMP = open, V
CS
= 0V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
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
CURRENT-LIMIT COMPARATOR
Current-Limit Trip Threshold
CS Input Bias Current
Propagation Delay from
Comparator Input to NDRV
IN CLAMP VOLTAGE
IN Clamp Voltage
ERROR AMPLIFIER
Voltage Gain
Unity-Gain Bandwidth
Phase Margin
FB Input Offset Voltage
COMP High Voltage
COMP Low Voltage
Source Current
Sink Current
Reference Voltage
Reference Voltage Accuracy
FB Input Bias Current
COMP Short-Circuit Current
DIGITAL SOFT-START
Soft-Start Duration
Reference Voltage Steps During
Soft-Start
Reference Voltage Step
t
SS
f
SW
= 350kHz
1984
5.6
31
39.67
NDRV
cycles
ms
Steps
mV
V
REF
(Note 3)
-1.5
-50
8
I
COMP
= 0A
I
COMP
= 0A
0.5
0.5
1.230
+1.5
+50
2.5
1.1
R
LOAD
= 100kΩ
R
LOAD
= 100kΩ, C
LOAD
= 200pF
R
LOAD
= 100kΩ, C
LOAD
= 200pF
80
2
65
±1
dB
MHz
Degrees
mV
V
V
mA
mA
V
%
nA
mA
V
INC
2mA sink current (Note 2)
24.1
26.1
29.0
V
V
CS
I
CS
t
PDCS
V
CS
= 0V
100mV overdrive
900
-4
60
1000
1100
+4
mV
μA
ns
V
PWM
I
CS
t
PWM
V
COMP
- V
CS
V
CS
= 0V
Change in V
CS
= 0.1V
1.24
-4
60
1.38
1.54
+4
V
μA
ns
R
ON(LOW)
Measured at NDRV sinking 100mA
R
ON(HIGH)
Measured at NDRV sourcing 20mA
2
4
1
0.65
4
10
Ω
A
A
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX17499/MAX17500
_______________________________________________________________________________________
3
Current-Mode PWM Controllers with
Programmable Switching Frequency
MAX17499/MAX17500
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= +12V (for MAX17500, bring V
IN
up to 23.6V for startup), 10nF bypass capacitors at IN and V
CC
, R12 = 15kΩ (MAX17499A/
MAX17500A), R12 = 7.5kΩ (MAX17499B/MAX17500B), R15 = 1kΩ, C6 = 100nF (see the
Typical Application Circuit),
NDRV = open,
V
UVLO/EN
= +1.4V, V
FB
= +1.0V, COMP = open, V
CS
= 0V, T
A
= -40°C to +125°C, unless otherwise noted. Typical values are at T
A
=
+25°C.) (Note 1)
PARAMETER
OSCILLATOR
Oscillator Frequency Range
Oscillator Frequency Accuracy
NDRV Switching Frequency
(Note 4)
Maximum Duty Cycle
f
SW
D
MAX
f
OSC
f
OSC
= 200kHz to 800kHz
f
OSC
= 50kHz to 2500kHz
MAX17499A/MAX17500A, f
SW
= f
OSC
/2
MAX17499B/MAX17500B, f
SW
= f
OSC
/4
MAX17499A/MAX17500A
MAX17499B/MAX17500B
50
-10
-20
25
12.5
50
75
2500
+10
+20
625
625.0
kHz
%
kHz
%
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Note 1:
All devices are 100% tested at T
A
= +125°C. All limits over temperature are guaranteed by characterization.
Note 2:
The MAX17500 is intended for use in universal input power supplies. The internal clamp circuit at IN is used to prevent the
bootstrap capacitor (C1 in Figure 1) from charging to a voltage beyond the absolute maximum rating of the device when
UVLO/EN is low (shutdown mode). Externally limit the maximum current to IN (hence to clamp) to 2mA maximum when
UVLO/EN is low. Clamp currents higher than 2mA may result in a clamp voltage higher than 30V, thus exceeding the
absolute maximum rating for IN. For the MAX17499, do not exceed the 24V maximum operating voltage of the device.
Note 3:
V
REF
is measured with FB connected to COMP (see the
Functional Diagram).
Note 4:
The oscillator in the MAX17499A/MAX17500A is capable of operating up to 2500kHz. However, the NDRV switching fre-
quency is limited to operate up to 625kHz. Thus, the oscillator frequency for the MAX17499A/MAX17500A must be limited to
1250kHz (maximum).
Typical Operating Characteristics
(V
UVLO/EN
= +1.4V, V
FB
= +1V, COMP = open, V
CS
= 0V, T
A
= +25°C, unless otherwise noted.)
BOOTSTRAP UVLO WAKE-UP LEVEL
vs. TEMPERATURE
MAX17499/500 toc01
BOOTSTRAP UVLO SHUTDOWN LEVEL
vs. TEMPERATURE
MAX17499/500 toc02
UVLO/EN WAKE-UP THRESHOLD
vs. TEMPERATURE
UVLO/EN RISING
1.234
1.232
1.230
1.228
MAX17499/500 toc03
21.8
MAX17500 V
IN
RISING
21.7
10.3
MAX17500 V
IN
FALLING
10.1
1.236
V
IN
(V)
21.5
V
IN
(V)
21.6
9.9
9.7
21.4
9.5
V
UVLO/EN
(V)
1.226
1.224
-40
21.3
-40
-15
10
35
60
85
9.3
-40
-15
10
35
60
85
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
4
_______________________________________________________________________________________
Current-Mode PWM Controllers with
Programmable Switching Frequency
Typical Operating Characteristics (continued)
(V
UVLO/EN
= +1.4V, V
FB
= +1V, COMP = open, V
CS
= 0V, T
A
= +25°C, unless otherwise noted.)
UVLO/EN SHUTDOWN THRESHOLD
vs. TEMPERATURE
MAX17499/500 toc04
MAX17499/MAX17500
V
IN
SUPPLY CURRENT IN UVLO
vs. TEMPERATURE
MAX17499/500 toc05
V
IN
SUPPLY CURRENT AFTER
STARTUP vs. TEMPERATURE
V
IN
= 24V
f
SW
= 350kHz
1.9
MAX17499/500 toc06
1.180
UVLO/EN FALLING
1.175
1.170
65
V
IN
= 19V
MAX17500 WHEN IN
BOOTSTRAP UVLO
60
I
START
(µA)
2.0
V
UVLO/EN
(V)
1.165
1.160
55
I
IN
(mA)
1.8
1.7
50
1.155
1.150
-40
45
-40
1.6
-15
10
35
60
85
-15
10
35
60
85
1.5
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
V
CC
REGULATOR SET POINT
vs. TEMPERATURE
V
IN
= 19V
NDRV NOT SWITCHING
9.6
V
CC
(V)
MAX17499/500 toc07
V
CC
REGULATOR SET POINT
vs. TEMPERATURE
MAX17499/500 toc08
CURRENT-LIMIT TRIP THRESHOLD
vs. TEMPERATURE
CURRENT-LIMIT TRIP THRESHOLD (V)
+3σ
1.01
1.00
MEAN
0.99
0.98
-3σ
0.97
TOTAL NUMBER OF DEVICES = 140
0.96
MAX17499/500 toc09
9.8
8.9
V
IN
= 19V
8.8
8.7
8.6
V
CC
(V)
10mA LOAD
1.02
9.4
NDRV SWITCHING
f
SW
= 350kHz
9.2
8.5
8.4
20mA LOAD
8.3
8.2
9.0
-40
8.1
-15
10
35
60
85
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
TEMPERATURE (°C)
-40
-15
10
35
60
85
TEMPERATURE (°C)
CURRENT-LIMIT TRIP THRESHOLD
MAX17499/500 toc10
SWITCHING FREQUENCY
vs. TEMPERATURE
MAX17499/500 toc11
SWITCHING FREQUENCY
TOTAL NUMBER
OF DEVICES = 140
MAX17499/500 toc12
60
50
PERCENTAGE OF UNITS (%)
40
30
20
10
0
0.964
TOTAL NUMBER
OF DEVICES = 140
355
+3σ
SWITCHING FREQUENCY (kHz)
350
345
MEAN
340
335
-3σ
330
TOTAL NUMBER OF DEVICES = 140
325
60
50
PERCENTAGE OF UNITS (%)
40
30
20
10
0
326.7
0.978
0.993
1.007
1.022
1.036
-40
-15
10
35
60
85
333.5
340.3
347.2
354.0
360.8
CURRENT-LIMIT TRIP THRESHOLD (V)
TEMPERATURE (°C)
SWITCHING FREQUENCY (kHz)
_______________________________________________________________________________________
5
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