19-3864; Rev 3; 10/06
High-Performance, Single-Ended, Current-Mode
PWM Controllers
General Description
The MAX5094A/B/C/D/MAX5095A/B/C BiCMOS, high-
performance, current-mode PWM controllers have all the
features required for wide input-voltage range
isolated/nonisolated power supplies. These controllers
are used for low- and high-power universal input volt-
age and telecom power supplies.
The MAX5094/MAX5095 contain a fast comparator with
only 60ns typical delay from current sense to the output
for overcurrent protection. The MAX5094 has an inte-
grated error amplifier with the output at COMP. Soft-
start is achieved by controlling the COMP voltage rise
using external components.
The oscillator frequency is adjustable from 20kHz to
1MHz with an external resistor and capacitor. The tim-
ing capacitor discharge current is trimmed allowing for
programmable dead time and maximum duty cycle for
a given frequency. The available saw-toothed waveform
at R
T
C
T
can be used for slope compensation when
needed.
The MAX5095A/MAX5095B include a bidirectional syn-
chronization circuit allowing for multiple controllers to
run at the same frequency to avoid beat frequencies.
Synchronization is accomplished by simply connecting
the SYNC of all devices together. When synchronizing
with other devices, the MAX5095A/MAX5095B with the
highest frequency synchronizes the other devices.
Alternatively, the MAX5095A/MAX5095B can be syn-
chronized to an external clock with an open-drain out-
put stage running at a higher frequency.
The MAX5095C provides a clock output pulse
(ADV_CLK) that leads the driver output (OUT) by
110ns. The advanced clock signal is used to drive the
secondary-side synchronous rectifiers.
The MAX5094A/B/C are available in the 8-pin SO and
8-pin µMAX
®
packages. The MAX5094D and
MAX5095A/B/C are available in the 8-pin µMAX pack-
age. All devices operate over the automotive tempera-
ture range of -40°C to +125°C.
Features
♦
Pin-for-Pin Replacement for UCC28C43
(MAX5094A) and UCC28C45 (MAX5094B)
♦
2A Drive Source and 1A Sink Capability
♦
Up to 1MHz Switching Frequency Operation
♦
Bidirectional Frequency Synchronization
(MAX5095A/MAX5095B)
♦
Advanced Output Drive for Secondary-Side
Synchronous Rectification (MAX5095C)
♦
Fast 60ns Cycle-by-Cycle Current Limit
♦
Trimmed Oscillator Capacitor Discharge Current
Sets Maximum Duty Cycle Accurately
♦
Accurate ±5% Start Voltage with 0.8V Hysteresis
♦
Low 32µA Startup Current
♦
5V Regulator Output (REF) with 20mA Capability
♦
Versions with 0.3V Current-Sense Threshold
♦
Overtemperature Shutdown
MAX5094A/B/C/D/MAX5095A/B/C
Ordering Information
PART
MAX5094AASA
MAX5094AASA+
MAX5094AAUA*
MAX5094AAUA+
MAX5094BASA*
MAX5094BASA+
MAX5094BAUA*
MAX5094BAUA+
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-
PACKAGE
8 SO
8 SO
8 µMAX
8 µMAX
8 SO
8 SO
8 µMAX
8 µMAX
PKG
CODE
S8-4
S8-4
U8-1
U8-1
S8-4
S8-4
U8-1
U8-1
+Denotes
lead-free package.
*Future
product—contact factory for availability.
Ordering Information continued at end of data sheet.
Pin Configurations
TOP VIEW
COMP
1
8
7
REF
V
CC
OUT
GND
Applications
Universal Input AC/DC Power Supplies
Isolated Telecom Power Supplies
Isolated Power-Supply Modules
Networking Systems
Computer Systems/Servers
Industrial Power Conversion
Isolated Keep-Alive Circuits
µMAX is a registered trademark of Maxim Integrated Products, Inc.
FB
2
MAX5094
CS
3
6
5
R
T
/C
T
4
µMAX/SO
Pin Configurations continued at end of data sheet.
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.
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
ABSOLUTE MAXIMUM RATINGS
V
CC
(Low-Impedance Source) to GND ..................-0.3V to +30V
V
CC
(I
CC
< 30mA).....................................................Self Limiting
OUT to GND ...............................................-0.3V to (V
CC
+ 0.3V)
OUT Current.............................................................±1A for 10µs
FB, SYNC, COMP, CS, R
T
/C
T
, REF to GND .............-0.3V to +6V
COMP Sink Current (MAX5094)..........................................10mA
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW
8-Pin SO (derate 5.9mW/°C above +70°C)...............470.6mW
Operating Temperature Range .........................-40°C to +125°C
Maximum Junction Temperature .....................................+150°C
Storage Temperature Range .............................-65°C to +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
CC
= +15V, R
T
= 10kΩ, C
T
= 3.3nF, REF = open, C
REF
= 0.1µF, COMP = open, V
FB
= 2V, CS = GND,
T
A
= T
J
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
REFERENCE
Output Voltage
Line Regulation
Load Regulation
Total Output Variation
Reference Output-Noise Voltage
Reference Output Short Circuit
OSCILLATOR
Initial Accuracy
Voltage Stability
Temp Stability
R
T
/C
T
Voltage Ramp (
P-P
)
R
T
/C
T
Voltage Ramp Valley
Discharge Current
Frequency Range
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
FB Input Bias Current
Open-Loop Voltage Gain
Unity-Gain Bandwidth
Power-Supply Rejection Ratio
COMP Sink Current
COMP Source Current
COMP Output High Voltage
COMP Output Low Voltage
CURRENT-SENSE AMPLIFIER
Gain (Notes 3, 4)
A
CS
(MAX5094A/MAX5094B)
(MAX5094C/D, MAX5095_)
2.85
2.85
3
3
3.26
3.40
V/V
V/V
V
FB
I
B(FB)
A
VOL
f
GBW
PSRR
I
SINK
I
SOURCE
V
COMPH
V
COMPL
12V
≤
V
CC
≤
25V (Note 2)
V
FB
= 2.7V, V
COMP
= 1.1V
V
FB
= 2.3V, V
COMP
= 5V
V
FB
= 2.3V, R
COMP
= 15kΩ to GND
V
FB
= 2.7V, R
COMP
= 15kΩ to REF
60
2
-0.5
5
2V
≤
V
COMP
≤
4V
FB shorted to COMP
2.465
2.5
-0.01
100
1
80
6
-1.2
5.8
0.1
1.1
-1.8
2.535
-0.1
V
µA
dB
MHz
dB
mA
mA
V
V
V
RAMP
V
RAMP_VALLEY
I
DIS
f
OSC
V
RT/CT
= 2V, T
A
= +25°C
V
RT/CT
= 2V, -40°C
≤
T
A
≤
+85°C
7.9
7.5
20
T
A
= +25°C
12V
≤
V
CC
≤
25V
-40°C
≤
T
A
≤
+85°C
51
54
0.2
0.5
1.7
1.1
8.3
8.3
8.7
9.0
1000
57
0.5
kHz
%
%
V
V
mA
kHz
V
REF
∆V
LINE
∆V
LOAD
V
REFT
V
NOISE
I
S_SC
T
A
= +25°C, I
REF
= 1mA
12V
≤
V
CC
≤
25V, I
REF
= 1mA
1mA
≤
I
REF
≤
20mA
1mA
≤
I
REF
≤
20mA, 12V
≤
V
CC
≤
25V
10Hz
≤
f
≤
10kHz, T
A
= +25°C
V
REF
= 0V
-30
4.9
50
-100
-180
4.950
5.000
0.4
6
5.050
4
25
5.1
V
mV
mV
V
µV
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
2
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +15V, R
T
= 10kΩ, C
T
= 3.3nF, REF = open, C
REF
= 0.1µF, COMP = open, V
FB
= 2V, CS = GND,
T
A
= T
J
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
Maximum Current-Sense Signal
Power-Supply Rejection Ratio
Input Bias Current
Delay From CS to OUT
MOSFET DRIVER
OUT Low-Side On-Resistance
OUT High-Side On-Resistance
I
SOURCE
(Peak)
I
SINK
(Peak)
Rise Time
Fall Time
UNDERVOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
Minimum Operating Voltage After
Turn-On
Undervoltage-Lockout Hysteresis
PWM
MAX5094A/MAX5094C/MAX5095A
Maximum Duty Cycle
Minimum Duty Cycle
SUPPLY CURRENT
Startup Supply Current
Operating Supply Current
Zener Bias Voltage at V
CC
THERMAL SHUTDOWN
Thermal Shutdown
Thermal Shutdown Hysteresis
SYNC Frequency Range
SYNC Clock Input High
Threshold
SYNC Clock Input Low Threshold
SYNC Clock Input Minimum
Pulse Width
SYNC Clock Output High Level
SYNC Clock Output Low Level
SYNC Leakage Current
T
SHDN
T
HYST
f
SYNC
V
SYNCINH
V
SYNCINL
t
PW_SYNCIN
V
SYNCOH
V
SYNCOL
I
SYNC
1mA external pulldown
R
SYNC
= 5kΩ
V
SYNC
= 0V
200
4.0
4.7
0
0.01
0.1
0.1
20
3.5
0.8
Junction temperature rising
150
4
1000
°C
°C
kHz
V
V
ns
V
V
µA
I
START
I
CC
V
Z
V
CC
= 7.5V
V
FB
= V
CS
= 0V
I
CC
= 25mA
24
32
3
26.5
65
5
µA
mA
V
D
MAX
D
MIN
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
94.5
48
96
49.8
97.5
50
0
%
%
V
CC_START
V
CC_MIN
UVLO
HYST
7.98
7.1
8.40
7.6
0.8
8.82
8.0
V
V
V
V
RDS_ONL
V
RDS_ONH
I
SOURCE
I
SINK
t
R
t
F
I
SINK
= 200mA
I
SOURCE
= 100mA
C
OUT
= 10nF
C
OUT
= 10nF
C
OUT
= 1nF
C
OUT
= 1nF
4.5
3.5
2
1
15
22
10
7
Ω
Ω
A
A
ns
ns
SYMBOL
V
CS_MAX
PSRR
I
CS
t
CS_DELAY
CONDITIONS
MAX5094A/B (Note 3)
MAX5094C/MAX5094D (Note 3)
V
COMP
= 5V, MAX5095
12V
≤
V
CC
≤
25V
V
COMP
= 0V
50mV overdrive
MIN
0.95
0.275
0.275
TYP
1
0.3
0.3
70
-1
60
-2.5
MAX
1.05
0.325
0.325
dB
µA
ns
V
UNITS
MAX5094A/B/C/D/MAX5095A/B/C
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
_______________________________________________________________________________________
3
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +15V, R
T
= 10kΩ, C
T
= 3.3nF, REF = open, C
REF
= 0.1µF, COMP = open, V
FB
= 2V, CS = GND,
T
A
= T
J
= -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
ADV_CLK (MAX5095C Only)
ADV_CLK High Voltage
ADV_CLK Low Voltage
ADV_CLK Output Pulse Width
ADV_CLK Rising Edge to OUT
Rising Edge
ADV_CLK Source and Sink
Current
V
ADV_CLKH
V
ADV_CLKL
t
PULSE
t
ADV_CLK
I
ADV_CLK
10
I
ADV_CLK
= 10mA source
I
ADV_CLK
= 10mA sink
85
110
2.4
3
0.4
V
V
ns
ns
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ELECTRICAL CHARACTERISTICS
(V
CC
= +15V, R
T
= 10kΩ, C
T
= 3.3nF, REF = open, C
REF
= 0.1µF, COMP = open, V
FB
= 2V, CS = GND,
T
A
= T
J
= -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
REFERENCE
Output Voltage
Line Regulation
Load Regulation
Total Output Variation
Reference Output-Noise Voltage
Reference Output Short Circuit
OSCILLATOR
Initial Accuracy
Voltage Stability
Temp Stability
R
T
/C
T
Voltage Ramp (
P-P
)
R
T
/C
T
Voltage Ramp Valley
Discharge Current
Frequency Range
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
FB Input Bias Current
Open-Loop Voltage Gain
Unity-Gain Bandwidth
Power-Supply Rejection Ratio
COMP Sink Current
COMP Source Current
COMP Output High Voltage
COMP Output Low Voltage
V
FB
I
B(FB)
A
VOL
f
GBW
PSRR
I
SINK
I
SOURCE
V
COMPH
V
COMPL
12V
≤
V
CC
≤
25V (Note 2)
V
FB
= 2.7V, V
COMP
= 1.1V
V
FB
= 2.3V, V
COMP
= 5V
V
FB
= 2.3V, R
COMP
=15kΩ to GND
V
FB
= 2.7V, R
COMP
= 15kΩ to REF
60
2
-0.5
5
2V
≤
V
COMP
≤
4V
FB shorted to COMP
2.465
2.5
-0.01
100
1
80
6
-1.2
5.8
0.1
1.1
-1.8
2.535
-0.1
V
µA
dB
MHz
dB
mA
mA
V
V
V
RAMP
V
RAMP_VALLEY
I
DIS
f
OSC
V
RT/CT
= 2V, T
A
= +25°C
V
RT/CT
= 2V, -40°C
≤
T
A
≤
+125°C
7.9
7.5
20
T
A
= +25°C
12V
≤
V
CC
≤
25V
-40°C
≤
T
A
≤
+125°C
51
54
0.2
1
1.7
1.1
8.3
8.3
8.7
9.0
1000
57
0.5
kHz
%
%
V
V
mA
kHz
V
REF
∆V
LINE
∆V
LOAD
V
REFT
V
NOISE
I
S_SC
T
A
= +25°C, I
REF
= 1mA
12V
≤
V
CC
≤
25V, I
REF
= 1mA
1mA
≤
I
REF
≤
20mA
1mA
≤
I
REF
≤
20mA, 12V
≤
V
CC
≤
25V
10Hz
≤
f
≤
10kHz, T
A
= +25°C
V
REF
= 0V
-30
4.9
50
-100
-180
4.950
5.000
0.4
6
5.050
4
25
5.1
V
mV
mV
V
µV
mA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
4
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= +15V, R
T
= 10kΩ, C
T
= 3.3nF, REF = open, C
REF
= 0.1µF, COMP = open, V
FB
= 2V, CS = GND,
T
A
= T
J
= -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
CURRENT-SENSE AMPLIFIER
Gain (Notes 3, 4)
A
CS
MAX5094A/MAX5094B
MAX5094C/D, MAX5095_
MAX5094A/B (Note 3)
Maximum Current-Sense Signal
Power-Supply Rejection Ratio
Input Bias Current
Delay From CS to OUT
MOSFET DRIVER
OUT Low-Side On-Resistance
OUT High-Side On-Resistance
I
SOURCE
(Peak)
I
SINK
(Peak)
Rise Time
Fall Time
UNDERVOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
Minimum Operating Voltage After
Turn-On
Undervoltage-Lockout Hysteresis
PWM
MAX5094A/MAX5094C/MAX5095A
Maximum Duty Cycle
Minimum Duty Cycle
SUPPLY CURRENT
Startup Supply Current
Operating Supply Current
Zener Bias Voltage at V
CC
THERMAL SHUTDOWN
Thermal Shutdown
Thermal Shutdown Hysteresis
SYNC Frequency Range
SYNC Clock Input High
Threshold
SYNC Clock Input-Low Threshold
SYNC Clock Input Minimum
Pulse Width
T
SHDN
T
HYST
f
SYNC
V
SYNCINH
V
SYNCINL
t
PW_SYNCIN
200
20
3.5
0.8
Junction temperature rising
150
4
1000
°C
°C
kHz
V
V
ns
I
START
I
CC
V
Z
V
CC
= 7.5V
V
FB
= V
CS
= 0V
I
CC
= 25mA
24
32
3
26.5
65
5
µA
mA
V
D
MAX
D
MIN
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
94.5
48
96
49.8
97.5
50
0
%
%
V
CC_START
V
CC_MIN
UVLO
HYST
7.98
7.1
8.4
7.6
0.8
8.82
8.0
V
V
V
V
RDS_ONL
V
RDS_ONH
I
SOURCE
I
SINK
t
R
t
F
I
SINK
= 200mA
I
SOURCE
= 100mA
C
OUT
= 10nF
C
OUT
= 10nF
C
OUT
= 1nF
C
OUT
= 1nF
4.5
3.5
2
1
15
22
12
9
Ω
Ω
A
A
ns
ns
V
CS_MAX
PSRR
I
CS
t
CS_DELAY
MAX5094C/MAX5094D (Note 3)
V
COMP
= 5V, MAX5095_
12V
≤
V
CC
≤
25V
V
COMP
= 0V
50mV overdrive
2.85
2.85
0.95
0.275
0.275
3
3
1
0.300
0.300
70
-1
60
-2.5
3.26
3.40
1.05
0.325
0.325
dB
µA
ns
V
V/V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX5094A/B/C/D/MAX5095A/B/C
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
_______________________________________________________________________________________
5
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