MAX5095CAUA [MAXIM]
High-Performance, Single-Ended, Current-Mode PWM Controllers; 高性能,单端,电流模式PWM控制器型号: | MAX5095CAUA |
厂家: | MAXIM INTEGRATED PRODUCTS |
描述: | High-Performance, Single-Ended, Current-Mode PWM Controllers |
文件: | 总22页 (文件大小:296K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
19-3864; Rev 3; 10/06
High-Performance, Single-Ended, Current-Mode
PWM Controllers
General Description
Features
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.
♦ 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)
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.
♦ 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
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
♦ Accurate 5ꢀ Start ꢁoltage with 0ꢂ8ꢁ Hysteresis
♦ Low 32µA Startup Current
♦ 5ꢁ Regulator Output (REF) with 20mA Capability
♦ ꢁersions with 0ꢂ3ꢁ Current-Sense Threshold
♦ Overtemperature Shutdown
at R C can be used for slope compensation when
T
T
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.
Ordering Information
PIN-
PKG
PART
TEMP RANGE
PACKAGE CODE
MAX5094AASA
MAX5094AASA+
MAX5094AAUA*
MAX5094AAUA+
MAX5094BASA*
MAX5094BASA+
MAX5094BAUA*
MAX5094BAUA+
-40°C to +125°C 8 SO
-40°C to +125°C 8 SO
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 SO
-40°C to +125°C 8 SO
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
S8-4
S8-4
U8-1
U8-1
S8-4
S8-4
U8-1
U8-1
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
+Denotes lead-free package.
*Future product—contact factory for availability.
Ordering Information continued at end of data sheet.
®
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.
Pin Configurations
Applications
TOP VIEW
Universal Input AC/DC Power Supplies
Isolated Telecom Power Supplies
Isolated Power-Supply Modules
Networking Systems
COMP
FB
1
2
3
4
8
7
6
5
REF
V
CC
MAX5094
CS
OUT
GND
Computer Systems/Servers
Industrial Power Conversion
Isolated Keep-Alive Circuits
R /C
T
T
µMAX/SO
Pin Configurations continued at end of data sheet.
µMAX is a registered trademark of Maxim Integrated Products, Inc.
________________________________________________________________ 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.
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ABSOLUTE MAXIMUM RATINGS
V
V
(Low-Impedance Source) to GND..................-0.3V to +30V
Continuous Power Dissipation (T = +70°C)
A
CC
CC CC
(I
< 30mA).....................................................Self Limiting
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
OUT to GND ...............................................-0.3V to (V
+ 0.3V)
CC
OUT Current............................................................. 1A for 10µs
FB, SYNC, COMP, CS, R /C , REF to GND .............-0.3V to +6V
T
T
COMP Sink Current (MAX5094)..........................................10mA
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
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +85°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
REFERENCE
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage
V
T
= +25°C, I = 1mA
REF
4.950
5.000
0.4
6
5.050
4
V
REF
A
Line Regulation
∆V
12V ≤ V ≤ 25V, I = 1mA
REF
mV
mV
V
LINE
LOAD
REFT
CC
Load Regulation
∆V
1mA ≤ I
1mA ≤ I
≤ 20mA
25
REF
REF
Total Output Variation
Reference Output-Noise Voltage
Reference Output Short Circuit
OSCILLATOR
V
≤ 20mA, 12V ≤ V ≤ 25V
4.9
-30
51
5.1
CC
V
10Hz ≤ f ≤ 10kHz, T = +25°C
50
µV
mA
NOISE
A
I
V
= 0V
REF
-100
-180
S_SC
Initial Accuracy
T
= +25°C
54
0.2
0.5
1.7
1.1
8.3
8.3
57
kHz
%
%
V
A
Voltage Stability
12V ≤ V
≤ 25V
0.5
CC
Temp Stability
-40°C ≤ T ≤ +85°C
A
R /C Voltage Ramp (
)
V
RAMP
T
T
P-P
R /C Voltage Ramp Valley
V
RAMP_VALLEY
V
T
T
V
V
= 2V, T = +25°C
7.9
7.5
20
8.7
9.0
RT/CT
RT/CT
A
Discharge Current
I
mA
DIS
= 2V, -40°C ≤ T ≤ +85°C
A
Frequency Range
f
1000
kHz
OSC
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
V
FB shorted to COMP
2.465
2.5
-0.01
100
1
2.535
-0.1
V
µA
dB
MHz
dB
mA
mA
V
FB
FB Input Bias Current
I
B(FB)
Open-Loop Voltage Gain
Unity-Gain Bandwidth
A
2V ≤ V
≤ 4V
VOL
COMP
f
GBW
Power-Supply Rejection Ratio
COMP Sink Current
PSRR
12V ≤ V
≤ 25V (Note 2)
60
2
80
CC
I
V
V
V
V
= 2.7V, V
= 2.3V, V
= 2.3V, R
= 2.7V, R
= 1.1V
6
SINK
FB
FB
FB
FB
COMP
COMP
COMP
COMP
COMP Source Current
COMP Output High Voltage
COMP Output Low Voltage
CURRENT-SENSE AMPLIFIER
I
= 5V
-0.5
5
-1.2
5.8
0.1
-1.8
1.1
SOURCE
V
= 15kΩ to GND
= 15kΩ to REF
COMPH
V
V
COMPL
(MAX5094A/MAX5094B)
2.85
2.85
3
3
3.26
3.40
V/V
V/V
Gain (Notes 3, 4)
A
CS
(MAX5094C/D, MAX5095_)
2
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +85°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MAX5094A/B (Note 3)
MAX5094C/MAX5094D (Note 3)
= 5V, MAX5095
MIN
0.95
TYP
MAX
1.05
UNITS
1
Maximum Current-Sense Signal
V
V
0.275
0.275
0.3
0.3
70
-1
0.325
0.325
CS_MAX
V
COMP
Power-Supply Rejection Ratio
Input Bias Current
PSRR
12V ≤ V
≤ 25V
dB
µA
ns
CC
I
V
= 0V
COMP
-2.5
CS
Delay From CS to OUT
t
50mV overdrive
60
CS_DELAY
MOSFET DRIꢁER
OUT Low-Side On-Resistance
OUT High-Side On-Resistance
V
I
I
= 200mA
4.5
3.5
2
10
7
Ω
Ω
RDS_ONL
SINK
V
= 100mA
= 10nF
RDS_ONH
SOURCE
I
I
(Peak)
I
C
C
C
C
A
SOURCE
SOURCE
OUT
OUT
OUT
OUT
(Peak)
I
= 10nF
= 1nF
= 1nF
1
A
SINK
SINK
Rise Time
Fall Time
t
15
22
ns
ns
R
t
F
UNDERꢁOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
V
7.98
7.1
8.40
7.6
8.82
8.0
V
V
V
CC_START
Minimum Operating Voltage After
Turn-On
V
CC_MIN
Undervoltage-Lockout Hysteresis
UVLO
0.8
HYST
PWM
MAX5094A/MAX5094C/MAX5095A
94.5
48
96
97.5
50
0
Maximum Duty Cycle
D
%
%
MAX
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
49.8
Minimum Duty Cycle
SUPPLY CURRENT
Startup Supply Current
Operating Supply Current
D
MIN
I
V
V
= 7.5V
32
3
65
5
µA
mA
V
START
CC
FB
I
= V = 0V
CS
CC
Zener Bias Voltage at V
V
I = 25mA
CC
24
26.5
CC
Z
THERMAL SHUTDOWN
Thermal Shutdown
T
Junction temperature rising
150
4
°C
°C
SHDN
Thermal Shutdown Hysteresis
T
HYST
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
SYNC Frequency Range
f
20
1000
0.8
kHz
V
SYNC
SYNC Clock Input High
Threshold
V
3.5
SYNCINH
SYNC Clock Input Low Threshold
V
V
SYNCINL
SYNC Clock Input Minimum
Pulse Width
t
200
4.0
ns
PW_SYNCIN
SYNC Clock Output High Level
SYNC Clock Output Low Level
SYNC Leakage Current
V
1mA external pulldown
4.7
0
V
V
SYNCOH
V
R
SYNC
SYNC
= 5kΩ
0.1
0.1
SYNCOL
I
V
= 0V
0.01
µA
SYNC
_______________________________________________________________________________________
3
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +85°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
ADꢁ_CLK (MAX5095C Only)
ADV_CLK High Voltage
ADV_CLK Low Voltage
V
I
I
= 10mA source
= 10mA sink
2.4
3
V
V
ADV_CLKH
ADV_CLK
V
0.4
ADV_CLKL
ADV_CLK
ADV_CLK Output Pulse Width
t
85
ns
PULSE
ADV_CLK Rising Edge to OUT
Rising Edge
t
I
110
ns
ADV_CLK
ADV_CLK Source and Sink
Current
10
mA
ADV_CLK
ELECTRICAL CHARACTERISTICS
(V
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +125°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
REFERENCE
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage
V
T
= +25°C, I = 1mA
REF
4.950
5.000
0.4
6
5.050
4
V
REF
A
Line Regulation
∆V
12V ≤ V ≤ 25V, I = 1mA
REF
mV
mV
V
LINE
LOAD
REFT
CC
Load Regulation
∆V
1mA ≤ I
1mA ≤ I
≤ 20mA
25
REF
REF
Total Output Variation
Reference Output-Noise Voltage
Reference Output Short Circuit
OSCILLATOR
V
≤ 20mA, 12V ≤ V ≤ 25V
4.9
-30
51
5.1
CC
V
10Hz ≤ f ≤ 10kHz, T = +25°C
50
µV
mA
NOISE
A
I
V
= 0V
REF
-100
-180
S_SC
Initial Accuracy
T
= +25°C
54
0.2
1
57
kHz
%
%
V
A
Voltage Stability
12V ≤ V
≤ 25V
0.5
CC
Temp Stability
-40°C ≤ T ≤ +125°C
A
R /C Voltage Ramp (
)
V
1.7
1.1
8.3
8.3
T
T
P-P
RAMP
R /C Voltage Ramp Valley
V
RAMP_VALLEY
V
T
T
V
V
= 2V, T = +25°C
7.9
7.5
20
8.7
9.0
RT/CT
RT/CT
A
Discharge Current
I
mA
DIS
= 2V, -40°C ≤ T ≤ +125°C
A
Frequency Range
f
1000
kHz
OSC
ERROR AMPLIFIER (MAX5094)
FB Input Voltage
V
FB shorted to COMP
2.465
2.5
-0.01
100
1
2.535
-0.1
V
µA
dB
MHz
dB
mA
mA
V
FB
FB Input Bias Current
I
B(FB)
Open-Loop Voltage Gain
Unity-Gain Bandwidth
Power-Supply Rejection Ratio
COMP Sink Current
A
VOL
2V ≤ V
≤ 4V
COMP
f
GBW
PSRR
12V ≤ V
≤ 25V (Note 2)
60
2
80
CC
I
V
V
V
V
= 2.7V, V
= 2.3V, V
= 2.3V, R
= 2.7V, R
= 1.1V
6
SINK
FB
FB
FB
FB
COMP
COMP
COMP
COMP
COMP Source Current
COMP Output High Voltage
COMP Output Low Voltage
I
= 5V
-0.5
5
-1.2
5.8
0.1
-1.8
1.1
SOURCE
V
=15kΩ to GND
= 15kΩ to REF
COMPH
V
V
COMPL
4
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +125°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V/V
CURRENT-SENSE AMPLIFIER
MAX5094A/MAX5094B
MAX5094C/D, MAX5095_
MAX5094A/B (Note 3)
2.85
2.85
3
3
1
3.26
3.40
Gain (Notes 3, 4)
A
CS
0.95
1.05
Maximum Current-Sense Signal
V
MAX5094C/MAX5094D (Note 3)
= 5V, MAX5095_
0.275
0.275
0.300
0.300
70
0.325
0.325
V
CS_MAX
PSRR
V
COMP
Power-Supply Rejection Ratio
Input Bias Current
12V ≤ V
≤ 25V
dB
µA
CC
I
V
= 0V
COMP
-1
-2.5
CS
Delay From CS to OUT
t
50mV overdrive
60
ns
CS_DELAY
MOSFET DRIꢁER
OUT Low-Side On-Resistance
OUT High-Side On-Resistance
V
I
I
= 200mA
4.5
3.5
2
12
9
Ω
Ω
RDS_ONL
SINK
V
= 100mA
= 10nF
RDS_ONH
SOURCE
I
I
(Peak)
I
C
C
C
C
A
SOURCE
SOURCE
OUT
OUT
OUT
OUT
(Peak)
I
= 10nF
= 1nF
= 1nF
1
A
SINK
SINK
Rise Time
Fall Time
t
15
22
ns
ns
R
t
F
UNDERꢁOLTAGE LOCKOUT/STARTUP
Startup Voltage Threshold
V
7.98
7.1
8.4
7.6
0.8
8.82
8.0
V
V
V
CC_START
Minimum Operating Voltage After
Turn-On
V
CC_MIN
Undervoltage-Lockout Hysteresis
UVLO
HYST
PWM
MAX5094A/MAX5094C/MAX5095A
94.5
48
96
97.5
50
0
Maximum Duty Cycle
D
%
%
MAX
MAX5094B/MAX5094D/MAX5095B/
MAX5095C
49.8
Minimum Duty Cycle
SUPPLY CURRENT
Startup Supply Current
Operating Supply Current
D
MIN
I
V
V
= 7.5V
32
3
65
5
µA
mA
V
START
CC
FB
I
= V = 0V
CS
CC
Zener Bias Voltage at V
V
I = 25mA
CC
24
26.5
CC
Z
THERMAL SHUTDOWN
Thermal Shutdown
T
Junction temperature rising
150
4
°C
°C
SHDN
Thermal Shutdown Hysteresis
T
HYST
SYNCHRONIZATION (MAX5095A/MAX5095B Only) (Note 5)
SYNC Frequency Range
f
20
1000
0.8
kHz
V
SYNC
SYNC Clock Input High
Threshold
V
3.5
SYNCINH
SYNC Clock Input-Low Threshold
V
V
SYNCINL
SYNC Clock Input Minimum
Pulse Width
t
200
ns
PW_SYNCIN
_______________________________________________________________________________________
5
High-Performance, Single-Ended, Current-Mode
PWM Controllers
ELECTRICAL CHARACTERISTICS (continued)
(V
= +15V, R = 10kΩ, C = 3.3nF, REF = open, C
= 0.1µF, COMP = open, V = 2V, CS = GND, T = T = -40°C to +125°C,
REF FB A J
CC
T
T
unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
1mA external pulldown
MIN
TYP
MAX
UNITS
SYNC Clock Output High Level
SYNC Clock Output Low Level
SYNC Leakage Current
V
4.0
4.7
0
V
V
SYNCOH
V
R
SYNC
SYNC
= 5kΩ
0.1
0.1
SYNCOL
I
V
= 0V
0.01
µA
SYNC
ADꢁ_CLK (MAX5095C Only)
ADV_CLK High Voltage
V
I
I
= 10mA source
= 10mA sink
2.4
3
V
V
ADV_CLKH
ADV_CLK
ADV_CLK Low Voltage
V
0.4
ADV_CLKL
ADV_CLK
ADV_CLK Output Pulse Width
t
85
ns
PULSE
ADV_CLK Rising Edge to OUT
Rising Edge
t
I
110
ns
ADV_CLK
ADV_CLK Source and Sink
Current
10
mA
ADV_CLK
Note 1: All devices are 100% tested at +25°C. All limits over temperature are guaranteed by design, not production tested.
Note 2: Guaranteed by design, not production tested.
Note 3: Parameter measured at trip point of latch with V = 0 (MAX5094 only).
FB
Note 4: Gain is defined as A = ∆V
/ ∆V , 0 ≤ V ≤ 0.8V for MAX5094A/MAX5094B, 0 ≤ V ≤ 0.2V for
COMP
CS CS CS
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.
Typical Operating Characteristics
(V
= 15V, T = +25°C, unless otherwise noted.)
A
CC
OPERATING SUPPLY CURRENT
vs. TEMPERATURE AFTER STARTUP
STARTUP CURRENT
vs. TEMPERATURE
BOOTSTRAP UVLO vs. TEMPERATURE
(f
OSC
= f = 300kHz)
SW
10
41
39
37
35
33
31
29
27
25
5.1
4.9
4.7
4.5
4.3
4.1
3.9
3.7
3.5
V
= 7.5V
C = 560pF
T
CC
9
8
7
6
5
4
3
V
RISING
CC
V
FALLING
CC
2
1
0
HYSTERESIS
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)
6
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Typical Operating Characteristics (continued)
(V
= 15V, T = +25°C, unless otherwise noted.)
A
CC
REFERENCE VOLTAGE
vs. TEMPERATURE
REFERENCE VOLTAGE
vs. SUPPLY VOLTAGE
REFERENCE VOLTAGE
vs. REFERENCE LOAD CURRENT
5.08
5.000
4.998
4.996
4.994
4.992
4.990
4.988
4.986
4.984
4.982
4.980
5.05
5.00
4.95
4.90
4.85
4.80
4.75
4.70
4.65
I
= 1mA
REF
5.06
5.04
5.02
5.00
4.98
4.96
4.94
4.92
4.90
I
= 1mA
REF
I
= 20mA
REF
-40 -25 -10
5
20 35 50 65 80 95 110 125
10 12 14 16 18 20 22 24 26
(V)
0
10
20
30
40
50
60
70
TEMPERATURE (°C)
V
CC
I
(mA)
REF
OSCILLATOR FREQUENCY (f
vs. TEMPERATURE
)
OSCILLATOR R /C DISCHARGE CURRENT
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
OSC
T T
vs. TEMPERATURE
8.04
8.02
8.00
7.98
7.96
7.94
7.92
7.90
7.88
550
540
530
520
510
500
490
480
470
460
450
100
90
80
70
60
50
40
30
20
10
0
R = 3.65kΩ
T
V
= 2V
MAX5094A/MAX5094C/MAX5095A
RT/CT
C = 560pF
T
MAX5094B/MAX5094D/MAX5095B/MAX5095C
R = 5kΩ
T
C = 560pF
T
-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)
CURRENT-SENSE TRIP THRESHOLD
vs. TEMPERATURE
CURRENT-SENSE TRIP THRESHOLD
vs. TEMPERATURE
MAXIMUM DUTY CYCLE vs. FREQUENCY
MAX5094A/MAX5094C/MAX5095A
1.10
1.08
1.06
1.04
1.02
1.00
0.98
0.96
0.94
0.92
0.90
0.40
0.38
0.36
0.34
0.32
0.30
0.28
0.26
0.24
0.22
0.20
100
90
80
70
60
50
40
30
20
10
0
MAX5094A/MAX5094B
MAX5094C/D: V = 0V
FB
MAX5095_: V
= 5V
COMP
C = 100pF
T
C = 1000pF
T
C = 220pF
T
C = 560pF
T
V
= 0V
FB
-40 -25 -10
5
20 35 50 65 80 95 110 125
-40 -25 -10
5
20 35 50 65 80 95 110 125
0
500 1000 1500 2000 2500 3000 3500 4000
OSCILLATOR FREQUENCY (kHz)
TEMPERATURE (°C)
TEMPERATURE (°C)
_______________________________________________________________________________________
7
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Typical Operating Characteristics (continued)
(V
= 15V, T = +25°C, unless otherwise noted.)
A
CC
OUT IMPEDANCE vs. TEMPERATURE
TIMING RESISTANCE
vs. OSCILLATOR FREQUENCY
OUT IMPEDANCE vs. TEMPERATURE
(R PMOS DRIVER)
(R
DS_ON
NMOS DRIVER)
DS_ON
= 100mA
1000
100
10
5.0
10
9
8
7
6
5
4
3
2
1
0
I
= 200mA
I
SINK
SOURCE
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
C = 1nF
T
C = 560pF
T
C = 220pF
T
C = 100pF
T
C = 10nF
T
C = 4.7nF
T
1
C = 3.3nF
T
C = 2.2nF
T
0.1
10,000
100,000
1,000,000
10,000,000
-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
100
COMP VOLTAGE LEVEL TO TURN
OFF DEVICE vs. TEMPERATURE
ERROR-AMPLIFIER OPEN-LOOP GAIN
AND PHASE vs. FREQUENCY
MAX5094/95 toc16
2.3
10
V
= 15V
CC
140
120
100
80
90
80
70
60
50
40
30
20
10
0
2.2
2.1
2.0
1.9
1.8
1.7
1.6
1.5
-15
-40
GAIN
-65
PHASE
-90
60
-115
-140
-165
-190
40
20
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
0.01
1
10 100 1k 10k 100k 1M
FREQUENCY (Hz)
10M 100M
TEMPERATURE (°C)
TEMPERATURE (°C)
ADV_CLK RISING EDGE TO OUT RISING
EDGE TIME vs. TEMPERATURE
ADV_CLK AND OUT WAVEFORMS
MAX5094/95 toc19
120
118
116
114
112
110
108
106
104
102
100
V
= 15V
CC
MAX5095C
MAX5095C
ADV_CLK
5V/div
LOAD = 4.75kΩ
OUT
10V/div
-40 -25 -10
5
20 35 50 65 80 95 110 125
t = 20ns/div
TEMPERATURE (°C)
8
_______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Typical Operating Characteristics (continued)
(V
= 15V, T = +25°C, unless otherwise noted.)
A
CC
SUPPLY CURRENT
vs. OSCILLATOR FREQUENCY
MAXIMUM DUTY CYCLE
vs. R MAX5094A/MAX5095A
OUT SOURCE AND SINK CURRENTS
T
MAX5094/95 toc20
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
100
90
80
70
60
50
40
30
20
V
C
= 15V
CC
MAX5095C
C = 100pF
T
= 10nF
OUT
V
OUT
10V/div
C = 1000pF
T
C = 560pF
T
T
A
= +125°C
C = 220pF
T
T
= -40°C
A
I
OUT
4A/div
C = 100nF
T
t = 400ns/div
20 120 220 320 420 520 620 720 820 920 1020
FREQUENCY (kHz)
100
1000
10,000
100,000
R (Ω)
T
Pin Descriptions
MAX5094_
PIN
1
NAME
COMP
FB
FUNCTION
Error-Amplifier Output. COMP can be used for soft-start.
Error-Amplifier Inverting Input
2
PWM Comparator and Overcurrent Protection Comparator Input. The current-sense signal is
compared to a signal proportional to the error-amplifier output voltage.
3
4
CS
Timing Resistor/Capacitor Connection. A resistor R from R /C to REF and capacitor C from R /C
T
T
T
T
T
T
R /C
T
T
to GND set the oscillator frequency.
Power-Supply Ground. Place the V
loops.
and REF bypass capacitors close to the IC to minimize ground
CC
5
6
7
GND
OUT
MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.
Power-Supply Input. Bypass V to GND with a 0.1µF ceramic capacitor or a parallel combination of
CC
V
CC
a 0.1µF and a higher value ceramic capacitor.
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.
8
REF
_______________________________________________________________________________________
9
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Pin Descriptions (continued)
MAX5095_
PIN
NAME
FUNCTION
MAX5095A/
MAX5095B
MAX5095C
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.
1
2
1
COMP
SYNC
Bidirectional Synchronization Input. When synchronizing with other
MAX5095A/MAX5095Bs, the higher frequency part synchronizes all other devices.
—
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).
—
2
ADV_CLK
CS
PWM Comparator/Overcurrent Protection Comparator Input. The current-sense signal is
compared to the level shifted voltage at COMP.
3
4
3
4
Timing Resistor/Capacitor Connection. A resistor R from R /C to REF and capacitor C
T
T
T
T
R /C
T
T
from R /C to GND set the oscillator frequency.
T
T
Power-Supply Ground. Place the V
minimize ground loops.
and REF bypass capacitors close to the IC to
CC
5
6
7
5
6
7
GND
OUT
MOSFET Driver Output. OUT connects to the gate of the external n-channel MOSFET.
Power-Supply Input. Bypass V to GND with a 0.1µF ceramic capacitor or a parallel
CC
V
CC
combination of a 0.1µF and a higher value ceramic capacitor.
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.
8
8
REF
10 ______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VP
MAX5094_
UVLO
8.4V/7.6V
2.5V
VOLTAGE-
DIVIDER
REFERENCE
2.5V
PREREGULATOR
5V
2.5V
V
7
CC
THERMAL
SHUTDOWN
26.5V
V
DD
EN-REF
REF
BG
8
5V REGULATOR
SNS
VP
REG_OK
EN-DRV-BAR
DELAY
VOLTAGE-
DIVIDER
1V (MAX5094A/B)
0.3V (MAX5094C/D)
ILIM
OUT
6
4
S
R
Q
CLK
CS
3
5
CPWM
OSC Q
GND
R /C
T
2R
T
VEA
FB
2
1
100% MAX DUTY CYCLE (MAX5094A/MAX5094C)
50% MAX DUTY CYCLE (MAX5094B/MAX5094D)
R
COMP
Figure 1. MAX5094_ Functional Diagram
feedback input (FB) and internal error amplifier. The
MAX5095A/MAX5095B include bidirectional synchroniza-
tion (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%.
Detailed Description
The MAX5094_/MAX5095_ current-mode PWM con-
trollers are designed for use as the control and regulation
core of flyback or forward topology switching power sup-
plies. 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 V
overvoltage during startup.
clamp prevents
CC
Eight different versions of the MAX5094/MAX5095 are
available as shown in the Selector Guide. The
MAX5094A/MAX5094B are the standard versions with a
______________________________________________________________________________________ 11
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VP
MAX5095A
MAX5095B
UVLO
8.4V/7.6V
2.5V
VOLTAGE-
DIVIDER
REFERENCE
2.5V
PREREGULATOR
5V
2.5V
V
7
CC
THERMAL
SHUTDOWN
26.5V
V
DD
EN-REF
REF
BG
8
5V REGULATOR
SNS
VP
REG_OK
EN-DRV-BAR
DELAY
VOLTAGE-
DIVIDER
0.3V
ILIM
OUT
6
4
S
R
Q
CLK
CS
3
5
CPWM
OSC Q
GND
100% MAX DUTY CYCLE (MAX5095A)
50% MAX DUTY CYCLE (MAX5095B)
2R
R /C
T T
COMP
1
R
BIDIRECTIONAL
SYNC
SYNC
2
Figure 2. MAX5095A/B Functional Diagram
The MAX5094/MAX5095 use a current-mode control loop
where the output of the error amplifier is compared to the
Current-Mode Control Loop
The advantages of current-mode control over voltage-
mode 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-by-
cycle basis. Secondly, the stability requirements of the
current-mode controller are reduced to that of a single-
pole system unlike the double pole in the voltage-mode
control scheme.
current-sense voltage (V ). When the current-sense sig-
CS
nal is lower than the inverting input of the CPWM com-
parator, the output of the comparator is low and the
switch is turned on at each clock pulse. When the cur-
rent-sense signal is higher than the inverting input of the
CPWM comparator, the output is high and the switch is
turned off.
12 ______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
VP
MAX5095C
UVLO
8.4V/7.6V
2.5V
VOLTAGE-
DIVIDER
REFERENCE
2.5V
PREREGULATOR
5V
2.5V
V
7
CC
THERMAL
SHUTDOWN
26.5V
V
DD
EN-REF
REF
8
BG
5V REGULATOR
SNS
VP
REG_OK
EN-DRV-BAR
DELAY
VOLTAGE-
DIVIDER
0.3V
ILIM
OUT
6
S
R
Q
CLK
CS
3
5
50% MAX DUTY CYCLE
CPWM
OSC Q
GND
2R
R /C
T T
4
COMP
1
R
ADV_CLK
2
Figure 3. MAX5095C Functional Diagram
Size the startup resistor, R , to supply both the maxi-
V
and Startup
ST
CC
mum startup bias (I
) of the device (65µA max)
In normal operation, V
is derived from a tertiary wind-
START
CC
and the charging current for C . The startup capacitor
ing of the transformer. However, at startup there is no
energy delivered through the transformer, thus a resistor
ST
C
t
must charge to 8.4V within the desired time period
(for example, 500ms). The size of the startup
ST
ST
must be connected from V
to the input power source
CC
capacitor depends on:
(see R and C in Figures 5 to 8). During startup, C
ST
ST
ST
charges up through R . The 5V reference generator,
ST
1) IC operating supply current at a programmed oscilla-
comparator, error amplifier, oscillator, and drive circuit
remain off during UVLO to reduce startup current below
tor frequency (f ).
OSC
2) The time required for the bias voltage, derived from
a bias winding, to go from 0 to 9V.
65µA. When V
reaches the undervoltage-lockout
threshold of 8.4V, the output driver begins to switch and
the tertiary winding supplies power to V . V has an
CC
3) The MOSFET total gate charge.
CC CC
internal 26.5V current-limited clamp at its input to protect
the device from overvoltage during startup.
4) The operating frequency of the converter (f ).
SW
______________________________________________________________________________________ 13
High-Performance, Single-Ended, Current-Mode
PWM Controllers
To calculate the capacitance required, use the following
formula:
The minimum discharge time of C from 8.4V to 7.6V
ST
must be greater than the soft-start time (t ).
SS
Undervoltage Lockout (UVLO)
The minimum turn-on supply voltage for the
MAX5094/MAX5095 is 8.4V. Once V reaches 8.4V,
the reference powers up. There is 0.8V of hysteresis
from the minimum turn-on voltage to the UVLO thresh-
I
+I
t
SS
(
]
)
[
CC
G
C
=
ST
V
CC
HYST
where:
I
= Q f
G SW
G
old. Once V
reaches 8.4V, the MAX5094/MAX5095
CC
operates with V
down to 7.6V. Once V
goes below
I
is the MAX5094/MAX5095s’ maximum internal sup-
CC
CC
CC
7.6V the device is in UVLO. When in UVLO, the quies-
cent supply current into V falls back to 32µA (typ),
ply current after startup (see the Typical Operating
Characteristics to find the I at a given f ). Q is the
CC
IN
OSC
is the converter
G
and OUT and REF are pulled low.
total gate charge for the MOSFET, f
SW
switching frequency, V
is the bootstrap UVLO hys-
HYST
MOSFET Driver
OUT drives an external n-channel MOSFET and swings
from GND to V . Ensure that V remains below the
teresis (0.8V), and t is the soft-start time, which is set
SS
by external circuitry.
CC
CC
Size the resistor R according to the desired startup
time period, t , for the calculated C . Use the follow-
ing equations to calculate the average charging current
(I ) and the startup resistor (R ):
ST
absolute maximum V
rating of the external MOSFET.
GS
ST
ST
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.
CST
ST
V
× C
ST
SUVR
I
=
CST
t
Bypass V
with one or more 0.1µF ceramic capacitors
ST
CC
to GND, placed close to the MAX5094/MAX5095. The
average current sourced to drive the external MOSFET
depends on the total gate charge (Q ) and operating
G
frequency of the converter. The power dissipation in the
MAX5094/MAX5095 is a function of the average output-
V
⎛
⎝
⎞
SUVR
2
V
−
⎜
⎟
⎠
INMIN
R
≅
ST
drive current (I
). Use the following equation to cal-
DRIVE
I
+ I
CST START
culate the power dissipation in the device due to I
:
DRIVE
Where V
is the minimum input supply voltage for
INMIN
I
= Q x f
DRIVE G SW
the application (36V for telecom), V
is the bootstrap
SUVR
PD = (I
+ I ) x V
CC CC
DRIVE
UVLO wake-up level (8.4V), and I
is the V supply
START
IN
where, I
is the operating supply current. See the
CC
current at startup (65µA, max). Choose a higher value for
than the one calculated above if longer startup times
Typical Operating Characteristics for the operating
R
ST
supply current at a given frequency.
can be tolerated to minimize power loss in R
.
ST
The equation for C above gives a good approximation
Error Amplifier (MAX5094)
The MAX5094 includes an internal error amplifier. The
inverting input is at FB and the noninverting input is inter-
nally 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:
ST
of C , yet neglects the current through R . Fine tune
ST
using:
ST
C
ST
⎡
⎢
⎢
⎢
⎢
⎤
⎥
⎥
⎥
⎥
⎛
⎞
V
− 8V
INMIN
I
+I −
G
CC
⎜
⎟
⎠
R
⎝
ST
C
=
(t
)
SS
ST
V
HYST
⎢
⎣
⎥
⎦
R1
R2
⎛
⎝
⎞
V
= 1+
× 2.5V
⎜
⎟
⎠
OUT
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.
where, R1 and R2 are from Figure 6.
14 ______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
MAX5095_Feedback
The MAX5095A/MAX5095B/MAX5095C use either an
external error amplifier when designed into a nonisolat-
ed 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.
Reference Output
REF is a 5V reference output that can source 20mA.
Bypass REF to GND with a 0.1µF capacitor.
Current Limit
The MAX5094/MAX5095 include a fast current-limit com-
parator to terminate the ON cycle during an overload or a
fault condition. The current-sense resistor (R ), connect-
CS
ed between the source of the MOSFET and GND, sets
the current limit. The CS input has a voltage trip level
(V ) of 1V (MAX5094A/B) or 0.3V (MAX5094C/D,
CS
MAX5095_). Use the following equation to calculate R
:
CS
V
CS
R
=
CS
I
P−P
Oscillator
I
is the peak current in the primary that flows through
P-P
The oscillator frequency is programmed by adding an
the MOSFET. When the voltage produced by this current
(through the current-sense resistor) exceeds the current-
limit 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.
external capacitor and resistor at R /C (see R and C
T
T
T
T
in the Typical Application Circuits). R is connected
T
from R /C to the 5V reference (REF) and C is con-
T
T
T
nected from R /C to GND. REF charges C through R
T
T
T
T
until its voltage reaches 2.8V. C then discharges
T
through an 8.3mA internal current sink until C ’s voltage
T
reaches 1.1V, at which time C is allowed to charge
T
through R again. The oscillator’s period will be the
T
sum of the charge and discharge times of C . Calculate
T
the charge time as
Synchronization (MAX5095A/MAX5095B)
t = 0.57 x R x C
C
T
T
SYNC
SYNC is a bidirectional input/output that outputs a syn-
chronizing 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
The discharge time is then
3
R ×C ×10
T
T
t
=
D
3
4.88×R −1.8×10
T
an external pulldown resistor (R
) between 500Ω
The oscillator frequency will then be
SYNC
and 5kΩ. As an input, SYNC accepts the output pulses
1
+ t
D
from other MAX5095A/MAX5095Bs.
f
=
OSC
t
Synchronize multiple MAX5095A/MAX5095Bs by con-
necting 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
C
For the MAX5094A/MAX5094C/MAX5095A, the convert-
er output switching frequency (f ) is the same as the
SW
oscillator frequency (f
). For the MAX5094B/
OSC
MAX5094D/MAX5095B/MAX5095C, the output switch-
ing frequency is 1/2 the oscillator frequency.
time (t ) of the oscillator (see the Oscillator section). The
D
pulse width of the SYNC output is equal to the time
required to discharge the stray capacitance at SYNC
through R
plus the C discharge time t . Adjust
SYNC
T D
R /C such that the minimum discharge time t is 200ns.
T
T
D
______________________________________________________________________________________ 15
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
R /C
synchronous rectification using the MAX5095C. The
T
T
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 syn-
chronous-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 high-
speed optocoupler. The 85ns pulse, with 3V drive volt-
age (10mA source), significantly reduces the
volt-second requirement of the pulse transformer and
the advanced pulse alleviates the need for a high-
speed optocoupler.
OUT
t
= 110ns
ADV_CLK
ADV_CLK
t
= 85ns
PULSE
Figure 4. ADV_CLK
Thermal Shutdown
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
V
IN
R
ST
V
OUT
C
ST
1
2
3
4
8
7
6
5
COMP
REF
R1
R2
FB
V
CC
MAX5094_
N
CS
OUT
GND
R
T
R /C
T
T
C
T
R
CS
Figure 5. MAX5094_ Typical Application Circuit (Isolated Flyback with Primary-Side Regulation)
16 ______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Typical Application Circuits (continued)
V
IN
R
ST
V
C
OUT
ST
1
2
3
4
8
7
6
5
COMP
REF
R1
R2
FB
V
MAX5094_
CC
N
CS
OUT
GND
R
T
R /C
T
T
C
T
R
CS
Figure 6. MAX5094_ Typical Application Circuit (Nonisolated Flyback)
V
IN
R
ST
SYNC
INPUT/OUTPUT
V
C
OUT
ST
R
SYNC
1
2
3
4
8
7
6
5
COMP
SYNC
CS
REF
MAX5095A
MAX5095B
V
CC
N
OUT
GND
R
T
R /C
T
T
C
T
R
CS
Figure 7. MAX5095A/MAX5095B Typical Application Circuit (Isolated Flyback)
______________________________________________________________________________________ 17
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Typical Application Circuits (continued)
V
D
V
V
IN
OUT
R
ST
N
QS
C
ST
N
V
D
QR
V
CC
N
REF
OUT
CS
R
T
MAX5095C
R /C
T
T
C
T
R
CS
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
V
V
V
IN
IN
IN
V
V
V
CC
CC
CC
N
N
N
REF
OUT
CS
REF
OUT
CS
REF
OUT
CS
R
R
R
T
T
T
MAX5095A
MAX5095B
MAX5095A
MAX5095B
MAX5095A
MAX5095B
R /C
T
R /C
T
R /C
T T
T
T
C
C
C
T
T
T
SYNC
SYNC
SYNC
GND
GND
GND
TO OTHER
MAX5095A/Bs
R
SYNC
Figure 9. Synchronization of MAX5095A/MAX5095B
______________________________________________________________________________________ 19
High-Performance, Single-Ended, Current-Mode
PWM Controllers
Selector Guide
UꢁLO
THRESHOLD
(ꢁ)
CS
THRESHOLD
(ꢁ)
MAX DUTY
CYCLE
(ꢀ)
COMPETITORS PART
NUMBER
PIN-
PACKAGE
PART
FEATURE
MAX5094AASA
MAX5094AAUA
MAX5094BASA
MAX5094BAUA
MAX5094CASA
MAX5094CAUA
MAX5094DAUA
MAX5095AAUA
MAX5095BAUA
MAX5095CAUA
Feedback
Feedback
Feedback
Feedback
Feedback
Feedback
Feedback
Sync
8.4
8.4
8.4
8.4
8.4
8.4
8.4
8.4
8.4
8.4
1
100
100
50
UCC28C43 2nd source
UCC28C43 2nd source
UCC28C45 2nd source
UCC28C45 2nd source
Improved UCC28C43
Improved UCC28C43
Improved UCC28C45
Improved UCC28C43
Improved UCC28C45
Improved UCC28C45
8 SO
1
8 µMAX
8 SO
1
1
50
8 µMAX
8 SO
0.3
0.3
0.3
0.3
0.3
0.3
100
100
50
8 µMAX
8 µMAX
8 µMAX
8 µMAX
8 µMAX
100
50
Sync
ADV_CLK
50
Pin Configurations (continued)
TOP VIEW
COMP
1
2
3
4
8
7
6
5
REF
COMP
ADV_CLK
CS
1
2
3
4
8
7
6
5
REF
SYNC
CS
V
CC
V
CC
MAX5095A
MAX5095B
MAX5095C
OUT
GND
OUT
GND
R /C
T
T
R /C
T T
µMAX
µMAX
Chip Information
Ordering Information (continued)
TRANSISTOR COUNT: 1987
PIN-
PKG
PART
TEMP RANGE
PROCESS: BiCMOS
PACKAGE CODE
MAX5094CASA*
MAX5094CASA+
MAX5094CAUA*
MAX5094CAUA+
MAX5094DAUA*
MAX5094DAUA+
MAX5095AAUA
-40°C to +125°C 8 SO
-40°C to +125°C 8 SO
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
S8-4
S8-4
U8-1
U8-1
U8-1
U8-1
U8-1
U8-1
U8-1
U8-1
U8-1
U8-1
MAX5095AAUA+* -40°C to +125°C 8 µMAX
MAX5095BAUA*
MAX5095BAUA+
MAX5095CAUA*
MAX5095CAUA+
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
-40°C to +125°C 8 µMAX
+Denotes lead-free package.
*Future product—contact factory for availability.
20 ______________________________________________________________________________________
High-Performance, Single-Ended, Current-Mode
PWM Controllers
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 wwwꢂmaxim-icꢂcom/packages.)
INCHES
MILLIMETERS
DIM
A
MIN
MAX
0.069
0.010
0.019
0.010
MIN
1.35
0.10
0.35
0.19
MAX
1.75
0.25
0.49
0.25
0.053
0.004
0.014
0.007
N
A1
B
C
e
0.050 BSC
1.27 BSC
E
0.150
0.228
0.016
0.157
0.244
0.050
3.80
5.80
0.40
4.00
6.20
1.27
E
H
H
L
VARIATIONS:
INCHES
1
MILLIMETERS
DIM
D
MIN
MAX
0.197
0.344
0.394
MIN
4.80
8.55
9.80
MAX
5.00
N
8
MS012
AA
TOP VIEW
0.189
0.337
0.386
D
8.75 14
10.00 16
AB
D
AC
D
C
A
B
0∞-8∞
e
A1
L
FRONT VIEW
SIDE VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, .150" SOIC
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0041
B
1
______________________________________________________________________________________ 21
High-Performance, Single-Ended, Current-Mode
PWM Controllers
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 wwwꢂmaxim-icꢂcom/packages.)
4X S
8
8
MILLIMETERS
INCHES
DIM MIN
MAX
MAX
MIN
-
-
0.043
0.006
0.037
0.014
0.007
0.120
1.10
0.15
0.95
0.36
0.18
3.05
A
0.002
0.030
0.010
0.005
0.116
0.05
0.75
0.25
0.13
2.95
A1
A2
b
E
H
Ø0.50±0.1
c
D
e
0.0256 BSC
0.65 BSC
0.6±0.1
E
H
0.116
0.188
0.016
0°
0.120
2.95
4.78
0.41
0°
3.05
5.03
0.66
6°
0.198
0.026
6°
L
1
1
α
S
0.6±0.1
0.0207 BSC
0.5250 BSC
BOTTOM VIEW
D
TOP VIEW
A1
A2
A
c
α
e
L
b
SIDE VIEW
FRONT VIEW
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, 8L uMAX/uSOP
APPROVAL
DOCUMENT CONTROL NO.
REV.
1
21-0036
J
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.
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