MAXIM MAX5095AAUA

19-3864; Rev 3; 10/06
High-Performance, Single-Ended, Current-Mode
PWM Controllers
The MAX5094A/B/C/D/MAX5095A/B/C BiCMOS, highperformance, 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 voltage 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 integrated error amplifier with the output at COMP. Softstart 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 timing capacitor discharge current is trimmed allowing for
programmable dead time and maximum duty cycle for
a given frequency. The available saw-toothed waveform
at RTCT can be used for slope compensation when
needed.
The MAX5095A/MAX5095B include a bidirectional synchronization 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 synchronized to an external clock with an open-drain output 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 package. All devices operate over the automotive temperature range of -40°C to +125°C.
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.
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
Ordering Information
PART
PINPACKAGE
TEMP RANGE
PKG
CODE
MAX5094AASA
-40°C to +125°C
8 SO
MAX5094AASA+
-40°C to +125°C
8 SO
S8-4
S8-4
MAX5094AAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5094AAUA+
-40°C to +125°C
8 µMAX
U8-1
MAX5094BASA*
-40°C to +125°C
8 SO
S8-4
MAX5094BASA+
-40°C to +125°C
8 SO
S8-4
MAX5094BAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5094BAUA+
-40°C to +125°C
8 µMAX
U8-1
+Denotes lead-free package.
*Future product—contact factory for availability.
Ordering Information continued at end of data sheet.
Pin Configurations
TOP VIEW
8
REF
7
VCC
3
6
OUT
RT/CT 4
5
GND
COMP
1
FB 2
MAX5094
CS
µMAX/SO
Pin Configurations continued at end of data sheet.
________________________________________________________________ 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.
1
MAX5094A/B/C/D/MAX5095A/B/C
General Description
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ABSOLUTE MAXIMUM RATINGS
VCC (Low-Impedance Source) to GND ..................-0.3V to +30V
VCC (ICC < 30mA).....................................................Self Limiting
OUT to GND ...............................................-0.3V to (VCC + 0.3V)
OUT Current.............................................................±1A for 10µs
FB, SYNC, COMP, CS, RT/CT, REF to GND .............-0.3V to +6V
COMP Sink Current (MAX5094)..........................................10mA
Continuous Power Dissipation (TA = +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
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
4.950
5.000
5.050
V
0.4
4
mV
6
25
mV
5.1
V
-180
mA
REFERENCE
Output Voltage
VREF
TA = +25°C, IREF = 1mA
Line Regulation
∆VLINE
12V ≤ VCC ≤ 25V, IREF = 1mA
Load Regulation
∆VLOAD
1mA ≤ IREF ≤ 20mA
Total Output Variation
VREFT
1mA ≤ IREF ≤ 20mA, 12V ≤ VCC ≤ 25V
Reference Output-Noise Voltage
VNOISE
10Hz ≤ f ≤ 10kHz, TA = +25°C
Reference Output Short Circuit
IS_SC
4.9
50
-100
µV
VREF = 0V
-30
Initial Accuracy
TA = +25°C
51
54
57
kHz
Voltage Stability
12V ≤ VCC ≤ 25V
0.2
0.5
%
Temp Stability
-40°C ≤ TA ≤ +85°C
0.5
%
VRAMP
1.7
V
VRAMP_VALLEY
1.1
OSCILLATOR
RT/CT Voltage Ramp (P-P)
RT/CT Voltage Ramp Valley
Discharge Current
IDIS
Frequency Range
fOSC
V
VRT/CT = 2V, TA = +25°C
7.9
8.3
8.7
VRT/CT = 2V, -40°C ≤ TA ≤ +85°C
7.5
8.3
9.0
20
1000
mA
kHz
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
VFB
FB shorted to COMP
FB Input Bias Current
IB(FB)
Open-Loop Voltage Gain
AVOL
Unity-Gain Bandwidth
fGBW
Power-Supply Rejection Ratio
PSRR
12V ≤ VCC ≤ 25V (Note 2)
ISINK
VFB = 2.7V, VCOMP = 1.1V
COMP Sink Current
2.465
2V ≤ VCOMP ≤ 4V
COMP Source Current
ISOURCE
VFB = 2.3V, VCOMP = 5V
COMP Output High Voltage
VCOMPH
VFB = 2.3V, RCOMP = 15kΩ to GND
COMP Output Low Voltage
VCOMPL
VFB = 2.7V, RCOMP = 15kΩ to REF
60
2.5
2.535
V
-0.01
-0.1
µA
100
dB
1
MHz
80
dB
2
6
-0.5
-1.2
5
5.8
mA
-1.8
mA
V
0.1
1.1
V
CURRENT-SENSE AMPLIFIER
Gain (Notes 3, 4)
2
ACS
(MAX5094A/MAX5094B)
2.85
3
3.26
V/V
(MAX5094C/D, MAX5095_)
2.85
3
3.40
V/V
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
Maximum Current-Sense Signal
SYMBOL
VCS_MAX
CONDITIONS
MIN
TYP
MAX
MAX5094A/B (Note 3)
0.95
1
1.05
MAX5094C/MAX5094D (Note 3)
0.275
0.3
0.325
VCOMP = 5V, MAX5095
0.275
0.3
0.325
UNITS
V
12V ≤ VCC ≤ 25V
70
VCOMP = 0V
-1
tCS_DELAY
50mV overdrive
60
OUT Low-Side On-Resistance
VRDS_ONL
ISINK = 200mA
4.5
10
Ω
OUT High-Side On-Resistance
VRDS_ONH
ISOURCE = 100mA
3.5
7
Ω
Power-Supply Rejection Ratio
Input Bias Current
PSRR
ICS
Delay From CS to OUT
dB
-2.5
µA
ns
MOSFET DRIVER
ISOURCE (Peak)
ISOURCE
COUT = 10nF
2
ISINK
COUT = 10nF
1
A
Rise Time
tR
COUT = 1nF
15
ns
Fall Time
tF
COUT = 1nF
22
ns
ISINK (Peak)
A
UNDERVOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
VCC_START
7.98
8.40
8.82
V
Minimum Operating Voltage After
Turn-On
VCC_MIN
7.1
7.6
8.0
V
Undervoltage-Lockout Hysteresis
UVLOHYST
0.8
V
PWM
Maximum Duty Cycle
DMAX
Minimum Duty Cycle
DMIN
MAX5094A/MAX5094C/MAX5095A
94.5
96
97.5
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
48
49.8
50
0
%
%
SUPPLY CURRENT
Startup Supply Current
VCC = 7.5V
32
65
µA
Operating Supply Current
ISTART
ICC
VFB = VCS = 0V
3
5
mA
Zener Bias Voltage at VCC
VZ
ICC = 25mA
24
26.5
V
THERMAL SHUTDOWN
Thermal Shutdown
TSHDN
Thermal Shutdown Hysteresis
THYST
Junction temperature rising
150
°C
4
°C
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
SYNC Frequency Range
SYNC Clock Input High
Threshold
SYNC Clock Input Low Threshold
SYNC Clock Input Minimum
Pulse Width
fSYNC
20
VSYNCINH
3.5
0.8
tPW_SYNCIN
200
VSYNCOH
1mA external pulldown
SYNC Clock Output Low Level
VSYNCOL
RSYNC = 5kΩ
ISYNC
VSYNC = 0V
4.0
kHz
V
VSYNCINL
SYNC Clock Output High Level
SYNC Leakage Current
1000
V
ns
4.7
V
0
0.1
V
0.01
0.1
µA
_______________________________________________________________________________________
3
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +85°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
2.4
3
MAX
UNITS
ADV_CLK (MAX5095C Only)
ADV_CLK High Voltage
VADV_CLKH
IADV_CLK = 10mA source
ADV_CLK Low Voltage
VADV_CLKL
IADV_CLK = 10mA sink
V
0.4
V
ADV_CLK Output Pulse Width
tPULSE
85
ns
ADV_CLK Rising Edge to OUT
Rising Edge
tADV_CLK
110
ns
ADV_CLK Source and Sink
Current
IADV_CLK
10
mA
ELECTRICAL CHARACTERISTICS
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
4.950
5.000
5.050
V
0.4
4
mV
6
25
mV
REFERENCE
Output Voltage
VREF
Line Regulation
∆VLINE
TA = +25°C, IREF = 1mA
12V ≤ VCC ≤ 25V, IREF = 1mA
Load Regulation
∆VLOAD
1mA ≤ IREF ≤ 20mA
Total Output Variation
VREFT
1mA ≤ IREF ≤ 20mA, 12V ≤ VCC ≤ 25V
Reference Output-Noise Voltage
VNOISE
10Hz ≤ f ≤ 10kHz, TA = +25°C
Reference Output Short Circuit
IS_SC
4.9
5.1
50
VREF = 0V
-30
Initial Accuracy
TA = +25°C
51
Voltage Stability
12V ≤ VCC ≤ 25V
-100
V
µV
-180
mA
54
57
kHz
0.2
0.5
%
OSCILLATOR
-40°C ≤ TA ≤ +125°C
Temp Stability
RT/CT Voltage Ramp (P-P)
RT/CT Voltage Ramp Valley
1
%
VRAMP
1.7
V
VRAMP_VALLEY
1.1
V
Discharge Current
IDIS
Frequency Range
fOSC
VRT/CT = 2V, TA = +25°C
7.9
8.3
8.7
VRT/CT = 2V, -40°C ≤ TA ≤ +125°C
7.5
8.3
9.0
20
1000
mA
kHz
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
VFB
FB shorted to COMP
2.465
2.5
2.535
V
-0.01
-0.1
µA
FB Input Bias Current
IB(FB)
Open-Loop Voltage Gain
AVOL
Unity-Gain Bandwidth
fGBW
Power-Supply Rejection Ratio
PSRR
12V ≤ VCC ≤ 25V (Note 2)
60
80
dB
COMP Sink Current
ISINK
VFB = 2.7V, VCOMP = 1.1V
2
6
mA
-0.5
-1.2
5
5.8
2V ≤ VCOMP ≤ 4V
COMP Source Current
ISOURCE
VFB = 2.3V, VCOMP = 5V
COMP Output High Voltage
VCOMPH
VFB = 2.3V, RCOMP =15kΩ to GND
COMP Output Low Voltage
VCOMPL
VFB = 2.7V, RCOMP = 15kΩ to REF
4
100
dB
1
MHz
0.1
_______________________________________________________________________________________
-1.8
mA
V
1.1
V
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
MAX5094A/MAX5094B
2.85
3
3.26
MAX5094C/D, MAX5095_
2.85
3
3.40
UNITS
CURRENT-SENSE AMPLIFIER
Gain (Notes 3, 4)
ACS
Maximum Current-Sense Signal
VCS_MAX
MAX5094A/B (Note 3)
0.95
1
1.05
MAX5094C/MAX5094D (Note 3)
0.275
0.300
0.325
VCOMP = 5V, MAX5095_
0.275
0.300
0.325
V/V
V
12V ≤ VCC ≤ 25V
70
VCOMP = 0V
-1
tCS_DELAY
50mV overdrive
60
OUT Low-Side On-Resistance
VRDS_ONL
ISINK = 200mA
4.5
12
Ω
OUT High-Side On-Resistance
VRDS_ONH
ISOURCE = 100mA
3.5
9
Ω
Power-Supply Rejection Ratio
Input Bias Current
PSRR
ICS
Delay From CS to OUT
dB
-2.5
µA
ns
MOSFET DRIVER
ISOURCE
COUT = 10nF
2
ISINK
COUT = 10nF
1
A
Rise Time
tR
COUT = 1nF
15
ns
Fall Time
tF
COUT = 1nF
22
ns
ISOURCE (Peak)
ISINK (Peak)
A
UNDERVOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
Minimum Operating Voltage After
Turn-On
Undervoltage-Lockout Hysteresis
VCC_START
7.98
8.4
8.82
V
VCC_MIN
7.1
7.6
8.0
V
UVLOHYST
0.8
V
PWM
Maximum Duty Cycle
DMAX
Minimum Duty Cycle
DMIN
MAX5094A/MAX5094C/MAX5095A
94.5
96
97.5
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
48
49.8
50
0
%
%
SUPPLY CURRENT
Startup Supply Current
VCC = 7.5V
32
65
µA
Operating Supply Current
ISTART
ICC
VFB = VCS = 0V
3
5
mA
Zener Bias Voltage at VCC
VZ
ICC = 25mA
24
26.5
V
150
°C
4
°C
THERMAL SHUTDOWN
Thermal Shutdown
TSHDN
Thermal Shutdown Hysteresis
THYST
Junction temperature rising
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
SYNC Frequency Range
fSYNC
20
SYNC Clock Input High
Threshold
VSYNCINH
3.5
SYNC Clock Input-Low Threshold
VSYNCINL
SYNC Clock Input Minimum
Pulse Width
tPW_SYNCIN
1000
V
0.8
200
kHz
V
ns
_______________________________________________________________________________________
5
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +15V, RT = 10kΩ, CT = 3.3nF, REF = open, CREF = 0.1µF, COMP = open, VFB = 2V, CS = GND, TA = TJ = -40°C to +125°C,
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
SYNC Clock Output High Level
VSYNCOH
1mA external pulldown
SYNC Clock Output Low Level
VSYNCOL
RSYNC = 5kΩ
SYNC Leakage Current
ISYNC
MIN
TYP
4.0
4.7
VSYNC = 0V
MAX
UNITS
V
0
0.1
V
0.01
0.1
µA
0.4
V
ADV_CLK (MAX5095C Only)
ADV_CLK High Voltage
VADV_CLKH
IADV_CLK = 10mA source
ADV_CLK Low Voltage
VADV_CLKL
IADV_CLK = 10mA sink
2.4
3
V
ADV_CLK Output Pulse Width
tPULSE
85
ns
ADV_CLK Rising Edge to OUT
Rising Edge
tADV_CLK
110
ns
ADV_CLK Source and Sink
Current
IADV_CLK
10
mA
All devices are 100% tested at +25°C. All limits over temperature are guaranteed by design, not production tested.
Guaranteed by design, not production tested.
Parameter measured at trip point of latch with VFB = 0 (MAX5094 only).
Gain is defined as A = ∆VCOMP / ∆VCS, 0 ≤ VCS ≤ 0.8V for MAX5094A/MAX5094B, 0 ≤ VCS ≤ 0.2V for
MAX5094C/MAX5094D/ MAX5095_.
Note 5: Output frequency equals oscillator frequency for MAX5094A/MAX5094C/MAX5095A. Output frequency is one-half oscillator
frequency for MAX5094B/MAX5094D/MAX5095B/MAX5095C.
Note 1:
Note 2:
Note 3:
Note 4:
Typical Operating Characteristics
(VCC = 15V, TA = +25°C, unless otherwise noted.)
7
39
37
VCC FALLING
ICC (µA)
6
5
4
5.1
35
CT = 560pF
4.9
4.7
33
MAX5094/95 toc03
VCC = 7.5V
ICC (mA)
8
41
MAX5094/95 toc02
VCC RISING
MAX5094/95 toc01
9
OPERATING SUPPLY CURRENT
vs. TEMPERATURE AFTER STARTUP
(fOSC = fSW = 300kHz)
STARTUP CURRENT
vs. TEMPERATURE
BOOTSTRAP UVLO vs. TEMPERATURE
10
VCC (V)
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
4.5
4.3
31
4.1
29
3.9
27
3.7
25
3.5
3
2
1
HYSTERESIS
0
6
MAX5094A/MAX5094C/MAX5095A
-40 -25 -10 5 20 35 50 65 80 95 110 125
-40 -25 -10 5 20 35 50 65 80 95 110 125
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
5.06
5.04
5.000
MAX5094/95 toc05
5.05
MAX5094/95 toc04
5.08
REFERENCE VOLTAGE
vs. SUPPLY VOLTAGE
REFERENCE VOLTAGE
vs. REFERENCE LOAD CURRENT
5.00
4.95
4.996
4.994
4.98
IREF = 20mA
4.96
4.992
4.990
4.988
4.986
4.75
4.92
4.70
4.90
4.65
4.982
4.980
0
10
20
30
40
50
60
OSCILLATOR FREQUENCY (fOSC)
vs. TEMPERATURE
OSCILLATOR RT/CT DISCHARGE CURRENT
vs. TEMPERATURE
510
500
490
480
470
8.00
450
16
18
20
22
24
100
90
7.98
7.96
7.94
MAX5094A/MAX5094C/MAX5095A
80
26
70
60
50
40
MAX5094B/MAX5094D/MAX5095B/MAX5095C
30
7.92
20
7.90
460
14
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
DUTY CYCLE (%)
520
8.02
12
VCC (V)
MAX5094/95 toc08
530
VRT/CT = 2V
RT/CT DISCHARGE CURRENT (mA)
MAX5094/95 toc07
IREF (mA)
8.04
10
70
TEMPERATURE (°C)
RT = 3.65kΩ
CT = 560pF
540
4.984
MAX5094/95 toc09
4.94
550
10
RT = 5kΩ
CT = 560pF
0
7.88
-40 -25 -10 5 20 35 50 65 80 95 110 125
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MAXIMUM DUTY CYCLE vs. FREQUENCY
MAX5094A/MAX5094C/MAX5095A
CURRENT-SENSE TRIP THRESHOLD
vs. TEMPERATURE
CURRENT-SENSE TRIP THRESHOLD
vs. TEMPERATURE
80
70
60
50
CT = 1000pF
40
CT = 560pF CT = 220pF
1.06
1.04
1.02
1.00
0.98
30
0.96
20
0.94
10
0.92
0
0.90
0
500 1000 1500 2000 2500 3000 3500 4000
OSCILLATOR FREQUENCY (kHz)
MAX5094A/MAX5094B
1.08
0.40
0.38
MAX5094C/D: VFB = 0V
MAX5095_: VCOMP = 5V
0.36
CS THRESHOLD (V)
CT = 100pF
1.10
CS THRESHOLD (V)
90
MAX5094/95 toc10
100
MAX5094/95 toc11b
-40 -25 -10 5 20 35 50 65 80 95 110 125
MAX5094/95 toc11a
OSCILLATOR FREQUENCY (kHz)
4.85
4.80
-40 -25 -10 5 20 35 50 65 80 95 110 125
DUTY CYCLE (%)
4.90
VREF (V)
VREF (V)
VREF (V)
IREF = 1mA
IREF = 1mA
4.998
5.02
5.00
MAX5094/95 toc06
REFERENCE VOLTAGE
vs. TEMPERATURE
0.34
0.32
0.30
0.28
0.26
0.24
0.22
VFB = 0V
0.20
-40 -25 -10 5 20 35 50 65 80 95 110 125
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
7
MAX5094A/B/C/D/MAX5095A/B/C
Typical Operating Characteristics (continued)
(VCC = 15V, TA = +25°C, unless otherwise noted.)
Typical Operating Characteristics (continued)
(VCC = 15V, TA = +25°C, unless otherwise noted.)
CT = 100pF
10
1
RDS_ON (Ω)
CT = 10nF
CT = 4.7nF
CT = 3.3nF
CT = 2.2nF
0.1
10,000
ISINK = 200mA
9
8
7
6
5
4
3
2
1
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
-40 -25 -10 5 20 35 50 65 80 95 110 125
FREQUENCY (Hz)
TEMPERATURE (°C)
TEMPERATURE (°C)
PROPAGATION DELAY FROM CURRENT-LIMIT
COMPARATOR TO OUT vs. TEMPERATURE
ERROR-AMPLIFIER OPEN-LOOP GAIN
AND PHASE vs. FREQUENCY
1,000,000
90
80
GAIN (dB)
40
VCC = 15V
2.2
-15
120
100
50
2.3
10
140
70
60
COMP VOLTAGE LEVEL TO TURN
OFF DEVICE vs. TEMPERATURE
MAX5094/95 toc16
MAX5094/95 toc15
100
10,000,000
-40
GAIN
-65
80
PHASE
60
-90
2.1
VCOMP (V)
100,000
PHASE (DEGREES)
RT (kΩ)
CT = 220pF
10
MAX5094/95 toc14
CT = 560pF
ISOURCE = 100mA
RDS_ON (Ω)
CT = 1nF
5.0
4.8
4.6
4.4
4.2
4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.6
2.4
2.2
2.0
MAX5094/95 toc13
MAX5094/95 toc12
1000
100
OUT IMPEDANCE vs. TEMPERATURE
(RDS_ON NMOS DRIVER)
OUT IMPEDANCE vs. TEMPERATURE
(RDS_ON PMOS DRIVER)
2.0
1.9
1.8
40
-115
20
20
-140
1.7
10
0
-165
1.6
-20
-190
10k 100k 1M 10M 100M
1.5
30
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
0.01 1
10 100 1k
TEMPERATURE (°C)
TEMPERATURE (°C)
ADV_CLK AND OUT WAVEFORMS
MAX5094/95 toc19
MAX5094/95 toc18
120
118
-40 -25 -10 5 20 35 50 65 80 95 110 125
FREQUENCY (Hz)
ADV_CLK RISING EDGE TO OUT RISING
EDGE TIME vs. TEMPERATURE
MAX5095C
116
VCC = 15V
MAX5095C
ADV_CLK
5V/div
LOAD = 4.75kΩ
TIME (ns)
114
112
110
108
OUT
10V/div
106
104
102
100
-40 -25 -10 5 20 35 50 65 80 95 110 125
t = 20ns/div
TEMPERATURE (°C)
8
MAX5094/95 toc17
TIMING RESISTANCE
vs. OSCILLATOR FREQUENCY
PROPAGATION DELAY (ns)
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
7.0
6.5
VOUT
10V/div
6.0
MAX5095C
CT = 100pF
ICC (mA)
5.5
IOUT
4A/div
5.0
TA = +125°C
4.5
TA = -40°C
4.0
3.5
90
CT = 1000pF
80
CT = 560pF
70
CT = 220pF
60
50
CT = 100nF
40
3.0
t = 400ns/div
100
MAX5094/95 toc21
VCC = 15V
COUT = 10nF
MAXIMUM DUTY CYCLE
vs. RT MAX5094A/MAX5095A
DUTY CYCLE (%)
MAX5094/95 toc20
2.5
30
2.0
20
20 120 220 320 420 520 620 720 820 920 1020
FREQUENCY (kHz)
MAX5094/95 toc22
SUPPLY CURRENT
vs. OSCILLATOR FREQUENCY
OUT SOURCE AND SINK CURRENTS
100
1000
10,000
100,000
RT (Ω)
Pin Descriptions
MAX5094_
PIN
NAME
FUNCTION
1
COMP
2
FB
Error-Amplifier Inverting Input
3
CS
PWM Comparator and Overcurrent Protection Comparator Input. The current-sense signal is
compared to a signal proportional to the error-amplifier output voltage.
4
RT/CT
Timing Resistor/Capacitor Connection. A resistor RT from RT/CT to REF and capacitor CT from RT/CT
to GND set the oscillator frequency.
5
GND
Power-Supply Ground. Place the VCC and REF bypass capacitors close to the IC to minimize ground
loops.
6
OUT
MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.
7
VCC
Power-Supply Input. Bypass VCC to GND with a 0.1µF ceramic capacitor or a parallel combination of
a 0.1µF and a higher value ceramic capacitor.
8
REF
5V Reference Output. Bypass REF to GND with a 0.1µF ceramic capacitor or a parallel combination
of a 0.1µF and a higher value ceramic capacitor no larger then 4.7µF.
Error-Amplifier Output. COMP can be used for soft-start.
_______________________________________________________________________________________
9
MAX5094A/B/C/D/MAX5095A/B/C
Typical Operating Characteristics (continued)
(VCC = 15V, TA = +25°C, unless otherwise noted.)
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Pin Descriptions (continued)
MAX5095_
PIN
NAME
FUNCTION
MAX5095A/
MAX5095B
MAX5095C
1
1
COMP
Current Limit/PWM Comparator Input. COMP is level-shifted and connected to the
inverting input of the PWM comparator. Pull up COMP to REF through a resistor and
connect an optocoupler from COMP to GND for proper operation.
2
—
SYNC
Bidirectional Synchronization Input. When synchronizing with other
MAX5095A/MAX5095Bs, the higher frequency part synchronizes all other devices.
—
2
ADV_CLK
3
3
CS
PWM Comparator/Overcurrent Protection Comparator Input. The current-sense signal is
compared to the level shifted voltage at COMP.
4
4
RT/CT
Timing Resistor/Capacitor Connection. A resistor RT from RT/CT to REF and capacitor CT
from RT/CT to GND set the oscillator frequency.
5
5
GND
Power-Supply Ground. Place the VCC and REF bypass capacitors close to the IC to
minimize ground loops.
6
6
OUT
MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.
10
Advance Clock Output. ADV_CLK is an 85ns clock output pulse preceding the rising
edge of OUT (see Figure 4). Use the pulse to drive the secondary-side synchronous
rectifiers through a pulse transformer or an optocoupler (see Figure 8).
7
7
VCC
Power-Supply Input. Bypass VCC to GND with a 0.1µF ceramic capacitor or a parallel
combination of a 0.1µF and a higher value ceramic capacitor.
8
8
REF
5V Reference Output. Bypass REF to GND with a 0.1µF ceramic capacitor or a parallel
combination of a 0.1µF and a higher value ceramic capacitor no larger than 4.7µF.
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
VP
MAX5094_
UVLO
2.5V
REFERENCE
2.5V
8.4V/7.6V
PREREGULATOR
5V
2.5V
7 VCC
THERMAL
SHUTDOWN
EN-REF
26.5V
VDD
BG 5V REGULATOR
SNS
EN-DRV-BAR
REG_OK
VOLTAGEDIVIDER
8 REF
VP
DELAY
VOLTAGEDIVIDER
1V (MAX5094A/B)
0.3V (MAX5094C/D)
ILIM
S
Q
6 OUT
CLK
R
CS 3
CPWM
GND 5
OSC Q
4 RT/CT
2R
VEA
FB 2
R
COMP 1
100% MAX DUTY CYCLE (MAX5094A/MAX5094C)
50% MAX DUTY CYCLE (MAX5094B/MAX5094D)
Figure 1. MAX5094_ Functional Diagram
Detailed Description
The MAX5094_/MAX5095_ current-mode PWM controllers are designed for use as the control and regulation
core of flyback or forward topology switching power supplies. These devices incorporate an integrated low-side
driver, adjustable oscillator, error amplifier (MAX5094_
only), current-sense amplifier, 5V reference, and external
synchronization capability (MAX5095A/MAX5095B only).
An internal +26.5V current-limited VCC clamp prevents
overvoltage during startup.
Eight different versions of the MAX5094/MAX5095 are
available as shown in the Selector Guide. The
MAX5094A/MAX5094B are the standard versions with a
feedback input (FB) and internal error amplifier. The
MAX5095A/MAX5095B include bidirectional synchronization (SYNC). This enables multiple MAX5095A/
MAX5095Bs to be connected and synchronized to the
device with the highest frequency. The MAX5095C
includes an ADV_CLK output, which precedes the
MAX5095C’s drive output (OUT) by 110ns. Figures 1, 2,
and 3 show the internal functional diagrams of the
MAX5094_, MAX5095A/MAX5095B, and MAX5095C,
respectively. The MAX5094A/MAX5094C/MAX5095A are
capable of 100% maximum duty cycle. The MAX5094B/
MAX5094D/MAX5095B/MAX5095C limit the maximum
duty cycle to 50%.
______________________________________________________________________________________
11
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VP
MAX5095A
MAX5095B
UVLO
2.5V
REFERENCE
2.5V
8.4V/7.6V
PREREGULATOR
5V
VOLTAGEDIVIDER
2.5V
7 VCC
THERMAL
SHUTDOWN
EN-REF
26.5V
VDD
BG 5V REGULATOR
SNS
EN-DRV-BAR
REG_OK
8 REF
VP
DELAY
VOLTAGEDIVIDER
0.3V
ILIM
S
Q
6 OUT
CLK
R
CS 3
CPWM
GND 5
OSC Q
100% MAX DUTY CYCLE (MAX5095A)
50% MAX DUTY CYCLE (MAX5095B)
2R
COMP 1
4 RT/CT
R
SYNC 2
BIDIRECTIONAL
SYNC
Figure 2. MAX5095A/B Functional Diagram
Current-Mode Control Loop
The advantages of current-mode control over voltagemode control are twofold. First, there is the feed-forward
characteristic brought on by the controller’s ability to
adjust for variations in the input voltage on a cycle-bycycle basis. Secondly, the stability requirements of the
current-mode controller are reduced to that of a singlepole system unlike the double pole in the voltage-mode
control scheme.
12
The MAX5094/MAX5095 use a current-mode control loop
where the output of the error amplifier is compared to the
current-sense voltage (VCS). When the current-sense signal is lower than the inverting input of the CPWM comparator, the output of the comparator is low and the
switch is turned on at each clock pulse. When the current-sense signal is higher than the inverting input of the
CPWM comparator, the output is high and the switch is
turned off.
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
VP
MAX5095C
UVLO
2.5V
REFERENCE
2.5V
8.4V/7.6V
PREREGULATOR
5V
2.5V
7 VCC
THERMAL
SHUTDOWN
EN-REF
26.5V
VDD
BG 5V REGULATOR
SNS
EN-DRV-BAR
REG_OK
VOLTAGEDIVIDER
8 REF
VP
DELAY
VOLTAGEDIVIDER
0.3V
ILIM
S
Q
6 OUT
CLK
R
CS 3
CPWM
GND 5
OSC Q
50% MAX DUTY CYCLE
2R
4 RT/CT
COMP 1
R
ADV_CLK 2
Figure 3. MAX5095C Functional Diagram
VCC and Startup
In normal operation, VCC is derived from a tertiary winding of the transformer. However, at startup there is no
energy delivered through the transformer, thus a resistor
must be connected from VCC to the input power source
(see RST and CST in Figures 5 to 8). During startup, CST
charges up through RST. The 5V reference generator,
comparator, error amplifier, oscillator, and drive circuit
remain off during UVLO to reduce startup current below
65µA. When V CC reaches the undervoltage-lockout
threshold of 8.4V, the output driver begins to switch and
the tertiary winding supplies power to VCC. VCC has an
internal 26.5V current-limited clamp at its input to protect
the device from overvoltage during startup.
Size the startup resistor, RST, to supply both the maximum startup bias (ISTART) of the device (65µA max)
and the charging current for CST. The startup capacitor
CST must charge to 8.4V within the desired time period
t ST (for example, 500ms). The size of the startup
capacitor depends on:
1) IC operating supply current at a programmed oscillator frequency (fOSC).
2) The time required for the bias voltage, derived from
a bias winding, to go from 0 to 9V.
3) The MOSFET total gate charge.
4) The operating frequency of the converter (fSW).
______________________________________________________________________________________
13
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
To calculate the capacitance required, use the following
formula:
CST =
[ICC + IG ](tSS )
VHYST
where:
IG = QG fSW
ICC is the MAX5094/MAX5095s’ maximum internal supply current after startup (see the Typical Operating
Characteristics to find the IIN at a given fOSC). QG is the
total gate charge for the MOSFET, fSW is the converter
switching frequency, VHYST is the bootstrap UVLO hysteresis (0.8V), and tSS is the soft-start time, which is set
by external circuitry.
Size the resistor RST according to the desired startup
time period, tST, for the calculated CST. Use the following equations to calculate the average charging current
(ICST) and the startup resistor (RST):
V
× CST
ICST = SUVR
t ST
VSUVR ⎞
⎛
⎜ VINMIN −
⎟
⎝
2 ⎠
RST ≅
ICST + ISTART
Where VINMIN is the minimum input supply voltage for
the application (36V for telecom), VSUVR is the bootstrap
UVLO wake-up level (8.4V), and ISTART is the VIN supply
current at startup (65µA, max). Choose a higher value for
RST than the one calculated above if longer startup times
can be tolerated to minimize power loss in RST.
The equation for CST above gives a good approximation
of CST, yet neglects the current through RST. Fine tune
CST using:
⎡
⎛V
− 8V ⎞ ⎤
⎢ ICC + IG − ⎜ INMIN
⎟⎥
RST
⎝
⎠⎥
⎢
CST = ⎢
⎥(t SS )
VHYST
⎢
⎥
⎢⎣
⎥⎦
The above startup method is applicable to circuits where
the tertiary winding has the same phase as the output
windings. Thus, the voltage on the tertiary winding at any
given time is proportional to the output voltage and goes
through the same soft-start period as the output voltage.
14
The minimum discharge time of CST from 8.4V to 7.6V
must be greater than the soft-start time (tSS).
Undervoltage Lockout (UVLO)
The minimum turn-on supply voltage for the
MAX5094/MAX5095 is 8.4V. Once VCC reaches 8.4V,
the reference powers up. There is 0.8V of hysteresis
from the minimum turn-on voltage to the UVLO threshold. Once VCC reaches 8.4V, the MAX5094/MAX5095
operates with VCC down to 7.6V. Once VCC goes below
7.6V the device is in UVLO. When in UVLO, the quiescent supply current into VCC falls back to 32µA (typ),
and OUT and REF are pulled low.
MOSFET Driver
OUT drives an external n-channel MOSFET and swings
from GND to VCC. Ensure that VCC remains below the
absolute maximum VGS rating of the external MOSFET.
OUT is a push-pull output with the on-resistance of the
PMOS typically 3.5Ω and the on-resistance of the NMOS
typically 4.5Ω. The driver can source 2A typically and
sink 1A typically. This allows for the MAX5094/MAX5095
to quickly turn on and off high gate-charge MOSFETs.
Bypass VCC with one or more 0.1µF ceramic capacitors
to GND, placed close to the MAX5094/MAX5095. The
average current sourced to drive the external MOSFET
depends on the total gate charge (QG) and operating
frequency of the converter. The power dissipation in the
MAX5094/MAX5095 is a function of the average outputdrive current (IDRIVE). Use the following equation to calculate the power dissipation in the device due to IDRIVE:
IDRIVE = QG x fSW
PD = (IDRIVE + ICC) x VCC
where, ICC is the operating supply current. See the
Typical Operating Characteristics for the operating
supply current at a given frequency.
Error Amplifier (MAX5094)
The MAX5094 includes an internal error amplifier. The
inverting input is at FB and the noninverting input is internally connected to a 2.5V reference. The internal error
amplifier is useful for nonisolated converter design (see
Figure 6) and isolated design with primary-side regulation
through a bias winding (see Figure 5). In the case of a
nonisolated power supply, the output voltage is:
R1 ⎞
⎛
VOUT = ⎜1 +
⎟ × 2.5V
⎝ R2 ⎠
where, R1 and R2 are from Figure 6.
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Reference Output
REF is a 5V reference output that can source 20mA.
Bypass REF to GND with a 0.1µF capacitor.
Oscillator
The oscillator frequency is programmed by adding an
external capacitor and resistor at RT/CT (see RT and CT
in the Typical Application Circuits). RT is connected
from RT/CT to the 5V reference (REF) and CT is connected from RT/CT to GND. REF charges CT through RT
until its voltage reaches 2.8V. CT then discharges
through an 8.3mA internal current sink until CT’s voltage
reaches 1.1V, at which time C T is allowed to charge
through RT again. The oscillator’s period will be the
sum of the charge and discharge times of CT. Calculate
the charge time as
tC = 0.57 x RT x CT
The discharge time is then
tD =
RT × CT × 103
4.88 × RT − 1.8 × 103
The oscillator frequency will then be
fOSC =
1
t C + tD
For the MAX5094A/MAX5094C/MAX5095A, the converter output switching frequency (fSW) is the same as the
oscillator frequency (f OSC ). For the MAX5094B/
MAX5094D/MAX5095B/MAX5095C, the output switching frequency is 1/2 the oscillator frequency.
Current Limit
The MAX5094/MAX5095 include a fast current-limit comparator to terminate the ON cycle during an overload or a
fault condition. The current-sense resistor (RCS), connected between the source of the MOSFET and GND, sets
the current limit. The CS input has a voltage trip level
(V CS ) of 1V (MAX5094A/B) or 0.3V (MAX5094C/D,
MAX5095_). Use the following equation to calculate RCS:
V
RCS = CS
IP−P
IP-P is the peak current in the primary that flows through
the MOSFET. When the voltage produced by this current
(through the current-sense resistor) exceeds the currentlimit comparator threshold, the MOSFET driver (OUT) will
turn the switch off within 60ns. In most cases, a small RC
filter is required to filter out the leading-edge spike on the
sense waveform. Set the time constant of the RC filter at
50ns. Use a current transformer to limit the losses in the
current-sense resistor and achieve higher efficiency
especially at low input-voltage operation.
Synchronization (MAX5095A/MAX5095B)
SYNC
SYNC is a bidirectional input/output that outputs a synchronizing pulse and accepts a synchronizing pulse
from other MAX5095A/MAX5095Bs (see Figures 7 and
9). As an output, SYNC is an open-drain p-channel
MOSFET driven from the internal oscillator and requires
an external pulldown resistor (RSYNC) between 500Ω
and 5kΩ. As an input, SYNC accepts the output pulses
from other MAX5095A/MAX5095Bs.
Synchronize multiple MAX5095A/MAX5095Bs by connecting their SYNC pins together. All devices connected
together will synchronize to the one operating at the
highest frequency. The rising edge of SYNC will precede
the rising edge of OUT by approximately the discharge
time (tD) of the oscillator (see the Oscillator section). The
pulse width of the SYNC output is equal to the time
required to discharge the stray capacitance at SYNC
through RSYNC plus the CT discharge time tD. Adjust
RT/CT such that the minimum discharge time tD is 200ns.
______________________________________________________________________________________
15
MAX5094A/B/C/D/MAX5095A/B/C
MAX5095_Feedback
The MAX5095A/MAX5095B/MAX5095C use either an
external error amplifier when designed into a nonisolated converter or an error amplifier and optocoupler
when designed into an isolated power supply. The
COMP input is level-shifted and connected to the
inverting terminal of the PWM comparator (CPWM).
Connect the COMP input to the output of the external
error amplifier for nonisolated design. Pull COMP high
externally to 5V (or REF) and connect the optocoupler
transistor as shown in Figures 7 and 8. COMP can be
used for soft-start and also as a shutdown. See the
Typical Operating Characteristics to find the turn-off
COMP voltage at different temperatures.
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Advance Clock Output (ADV_CLK) (MAX5095C)
ADV_CLK is an advanced pulse output provided to
facilitate the easy implementation of secondary-side
synchronous rectification using the MAX5095C. The
ADV_CLK pulse width is 85ns (typically) with its rising
edge leading the rising edge of OUT by 110ns. Use
this leading pulse to turn off the secondary-side synchronous-rectifier MOSFET (QS) before the voltage
appears on the secondary (see Figure 8). Turning off
the secondary-side synchronous MOSFET earlier
avoids the shorting of the secondary in the forward
converter. The ADV_CLK pulse can be propagated to
the secondary side using a pulse transformer or highspeed optocoupler. The 85ns pulse, with 3V drive voltage (10mA source), significantly reduces the
volt-second requirement of the pulse transformer and
the advanced pulse alleviates the need for a highspeed optocoupler.
RT/CT
OUT
tADV_CLK = 110ns
ADV_CLK
tPULSE = 85ns
Thermal Shutdown
Figure 4. ADV_CLK
When the MAX5094/MAX5095’s die temperature goes
above +150°C, the thermal shutdown circuitry will shut
down the 5V reference and pull OUT low.
Typical Application Circuits
VIN
RST
VOUT
CST
1
R1
2
R2
RT
3
4
COMP
REF
FB
MAX5094_ VCC
CS
OUT
RT/CT
GND
8
7
6
N
5
CT
RCS
Figure 5. MAX5094_ Typical Application Circuit (Isolated Flyback with Primary-Side Regulation)
16
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VIN
RST
VOUT
CST
1
R1
2
R2
3
RT
4
COMP
REF
FB
MAX5094_ VCC
CS
OUT
RT/CT
GND
8
7
6
N
5
CT
RCS
Figure 6. MAX5094_ Typical Application Circuit (Nonisolated Flyback)
VIN
RST
SYNC
INPUT/OUTPUT
VOUT
CST
RSYNC
1
2
RT
3
4
COMP
REF
SYNC MAX5095A
VCC
MAX5095B
CS
OUT
RT/CT
GND
8
7
6
N
5
CT
RCS
Figure 7. MAX5095A/MAX5095B Typical Application Circuit (Isolated Flyback)
______________________________________________________________________________________
17
MAX5094A/B/C/D/MAX5095A/B/C
Typical Application Circuits (continued)
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5094A/B/C/D/MAX5095A/B/C
Typical Application Circuits (continued)
VD
VIN
VOUT
RST
N
QS
CST
N
QR
VD
VCC
REF
RT
N
OUT
MAX5095C
RT/CT
CS
CT
RCS
COMP
ADV_CLK
MAX5078
GND
0.5V/µs PULSE TRANSFORMER
Figure 8. MAX5095C Typical Application Circuit (Isolated Forward with Secondary-Side Synchronous Rectification)
18
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VIN
VIN
VCC
REF
RT
VCC
OUT
REF
RT
MAX5095A
MAX5095B
RT/CT
N
VCC
OUT
N
N
MAX5095A
MAX5095B
CS
CT
SYNC
GND
OUT
RT/CT
CS
CT
SYNC
REF
RT
MAX5095A
MAX5095B
RT/CT
CS
CT
MAX5094A/B/C/D/MAX5095A/B/C
VIN
SYNC
GND
GND
TO OTHER
MAX5095A/Bs
RSYNC
Figure 9. Synchronization of MAX5095A/MAX5095B
______________________________________________________________________________________
19
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Selector Guide
FEATURE
UVLO
THRESHOLD
(V)
CS
THRESHOLD
(V)
MAX DUTY
CYCLE
(%)
COMPETITORS PART
NUMBER
MAX5094AASA
Feedback
8.4
1
100
UCC28C43 2nd source
8 SO
MAX5094AAUA
Feedback
8.4
1
100
UCC28C43 2nd source
8 µMAX
MAX5094BASA
Feedback
8.4
1
50
UCC28C45 2nd source
8 SO
MAX5094BAUA
Feedback
8.4
1
50
UCC28C45 2nd source
8 µMAX
MAX5094CASA
Feedback
8.4
0.3
100
Improved UCC28C43
8 SO
PART
PINPACKAGE
MAX5094CAUA
Feedback
8.4
0.3
100
Improved UCC28C43
8 µMAX
MAX5094DAUA
Feedback
8.4
0.3
50
Improved UCC28C45
8 µMAX
MAX5095AAUA
Sync
8.4
0.3
100
Improved UCC28C43
8 µMAX
MAX5095BAUA
Sync
8.4
0.3
50
Improved UCC28C45
8 µMAX
MAX5095CAUA
ADV_CLK
8.4
0.3
50
Improved UCC28C45
8 µMAX
Pin Configurations (continued)
TOP VIEW
COMP 1
SYNC
CS
2
3
MAX5095A
MAX5095B
RT/CT 4
8
REF
COMP 1
7
VCC
ADV_CLK 2
7
VCC
6
OUT
CS
3
6
OUT
5
GND
RT/CT 4
5
GND
µMAX
Ordering Information (continued)
TEMP RANGE
REF
MAX5095C
µMAX
PART
8
PINPACKAGE
PKG
CODE
MAX5094CASA*
-40°C to +125°C
8 SO
MAX5094CASA+
-40°C to +125°C
8 SO
S8-4
MAX5094CAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5094CAUA+
-40°C to +125°C
8 µMAX
U8-1
MAX5094DAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5094DAUA+
-40°C to +125°C
8 µMAX
U8-1
Chip Information
TRANSISTOR COUNT: 1987
PROCESS: BiCMOS
S8-4
MAX5095AAUA
-40°C to +125°C
8 µMAX
U8-1
MAX5095AAUA+*
-40°C to +125°C
8 µMAX
U8-1
MAX5095BAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5095BAUA+
-40°C to +125°C
8 µMAX
U8-1
MAX5095CAUA*
-40°C to +125°C
8 µMAX
U8-1
MAX5095CAUA+
-40°C to +125°C
8 µMAX
U8-1
+Denotes lead-free package.
*Future product—contact factory for availability.
20
______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
N
E
H
INCHES
MILLIMETERS
MAX
MIN
0.069
0.053
0.010
0.004
0.014
0.019
0.007
0.010
0.050 BSC
0.150
0.157
0.228
0.244
0.016
0.050
MAX
MIN
1.35
1.75
0.10
0.25
0.35
0.49
0.19
0.25
1.27 BSC
3.80
4.00
5.80
6.20
0.40
SOICN .EPS
DIM
A
A1
B
C
e
E
H
L
1.27
VARIATIONS:
1
INCHES
TOP VIEW
DIM
D
D
D
MIN
0.189
0.337
0.386
MAX
0.197
0.344
0.394
MILLIMETERS
MIN
4.80
8.55
9.80
MAX
5.00
8.75
10.00
N MS012
8
AA
14
AB
16
AC
D
A
B
e
C
0∞-8∞
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
21-0041
REV.
B
1
1
______________________________________________________________________________________
21
MAX5094A/B/C/D/MAX5095A/B/C
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
4X S
8
E
Ø0.50±0.1
8
INCHES
DIM
A
A1
A2
b
H
c
D
e
E
H
0.6±0.1
1
L
1
α
0.6±0.1
S
BOTTOM VIEW
D
MIN
0.002
0.030
MAX
0.043
0.006
0.037
0.014
0.010
0.007
0.005
0.120
0.116
0.0256 BSC
0.120
0.116
0.198
0.188
0.026
0.016
6°
0°
0.0207 BSC
8LUMAXD.EPS
MAX5094A/B/C/D/MAX5095A/B/C
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MILLIMETERS
MAX
MIN
0.05
0.75
1.10
0.15
0.95
0.25
0.36
0.13
0.18
2.95
3.05
0.65 BSC
2.95
3.05
4.78
5.03
0.41
0.66
0°
6°
0.5250 BSC
TOP VIEW
A1
A2
e
A
α
c
b
FRONT VIEW
L
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 8L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
21-0036
REV.
J
1
1
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
22 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600
© 2006 Maxim Integrated Products
is a registered trademark of Maxim Integrated Products, Inc.