MAX5021EUT+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX5021EUT+T ,Current-Mode PWM Controllers for Isolated Power SuppliesApplicationsMAX5021EUA 50% -40°C to +85°C 8 μMAX —Universal Off-Line Power SuppliesMAX5021EPA 50% ..
MAX5023LASA ,65V, low-quiescent-current, high-voltage linear regulator with mP reset and watchdog timerMAX5023/MAX502419-2619; Rev 0; 10/0265V, Low-Quiescent-Current, High-Voltage LinearRegulators with ..
MAX5023LASA+ ,65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog TimerFeaturesThe MAX5023/MAX5024 high-voltage linear regulators ● Wide Operating Input Voltage Range +6. ..
MAX5023MASA ,65V, low-quiescent-current, high-voltage linear regulator with mP reset and watchdog timerFeaturesThe MAX5023/MAX5024 high-voltage linear regulators Wide Operating Input Voltage Rangeopera ..
MAX5023MASA+ ,65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog TimerFeaturesThe MAX5023/MAX5024 high-voltage linear regulators ● Wide Operating Input Voltage Range +6. ..
MAX5023MASA+T ,65V, Low-Quiescent-Current, High-Voltage Linear Regulators with µP Reset and Watchdog TimerApplicationsRESET RESET● AutomotiveONOFFEN● IndustrialWDI I/O● Home SecurityI/OHOLD● Fire/Smoke Ala ..
MAX919ESA+ ,SOT23, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Referenceapplications,Beyond-the-Railsincluding monitoring/management. ♦ CMOS Push-Pull Output with ±8mA Dri ..
MAX919EUK+ ,SOT23, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without ReferenceELECTRICAL CHARACTERISTICS—MAX917/MAX918(V = +5V, V = 0V, V = V , T = -40°C to +85°C, unless otherw ..
MAX919EUK+T ,SOT23, 1.8V, Nanopower, Beyond-the-Rails Comparators With/Without Referencefeatures make the MAX917–MAX920 family of♦ Input Voltage Range Extends 200mV comparators ideal for ..
MAX919EUK-T ,SOT23 / 1.8V / Nanopower / Beyond-the-Rails Comparators With/Without ReferenceELECTRICAL CHARACTERISTICS—MAX917/MAX918(V = +5V, V = 0, V = V , T = -40°C to +85°C, unless otherwi ..
MAX919EUK-T ,SOT23 / 1.8V / Nanopower / Beyond-the-Rails Comparators With/Without ReferenceELECTRICAL CHARACTERISTICS—MAX917/MAX918 (continued)(V = +5V, V = 0, V = V , T = -40°C to +85°C, un ..
MAX9201ESE+T ,Low-Cost, 7ns, Low-Power Voltage ComparatorsApplicationsMAX9201ESE -40°C to +85°C 16 Narrow SOHigh-Speed A/D Threshold DetectorsMAX9202EUD -40° ..

MAX5021EUT+T
Current-Mode PWM Controllers for Isolated Power Supplies
General Description
The MAX5021/MAX5022 current-mode PWM controllers
contain all the control circuitry required for the design
of wide input voltage range isolated power supplies.
These devices are well suited for use in universal input
(85VAC to 265VAC) off-line or telecom (-36VDC to
-72VDC) power supplies.
An undervoltage lockout (UVLO) circuit with large hys-
teresis coupled with low startup and operating current
reduce power dissipation in the startup resistor and
allow use of ceramic bypass capacitors. The 262kHz
switching frequency is internally trimmed to ±12%
accuracy; this allows the optimization of the magnetic
and filter components resulting in compact, cost-effec-
tive power supplies. The MAX5021 with 50% maximum
duty cycle and MAX5022 with 75% maximum duty
cycle are recommended for forward converters and fly-
back converters, respectively. The MAX5021/MAX5022
are available in 6-pin SOT23, 8-pin µMAX, and 8-pin
DIP packages and are rated for operation over the
-40°C to +85°C temperature range.
Applications
Universal Off-Line Power Supplies
Standby Power Supplies
Isolated Power Supplies
Isolated Telecom Power Supplies
Mobile Phone Chargers
FeaturesAvailable in a Tiny 6-Pin SOT23 Package50µA Typical Startup Current1.2mA Typical Operating CurrentLarge UVLO Hysteresis of 14VFixed Switching Frequency of 262kHz ±12%50% Maximum Duty Cycle Limit (MAX5021)75% Maximum Duty Cycle Limit (MAX5022)60ns Cycle-by-Cycle Current-Limit Response
Time
MAX5021/MAX5022
Current-Mode PWM Controllers for Isolated
Power Supplies
GND
VCCNDRVOPTOVIN
MAX5021
MAX5022
SOT23
TOP VIEW
NDRV
N.C.N.C.
GNDVIN
VCC
OPTO
PDIP/μMAX
MAX5021
MAX5022
Pin Configuration
Ordering Information
MAX5021
MAX5022
VOUT
VSUPPLY
OPTONDRV
VCCVIN
GND
Typical Operating Circuit
19-2066; Rev 1; 9/01
EVALUATION KIT AVAILABLE
PART
MAX
DUTY
CYCLE
TEMP.
RANGE
PIN-
PACKAGE
TOP
MARK
MAX5021EUT50%-40°C to +85°C 6 SOT23-6AASQ
MAX5021EUA50%-40°C to +85°C 8 μMAX—
MAX5021EPA50%-40°C to +85°C 8 PDIP—
MAX5022EUT75%-40°C to +85°C 6 SOT23-6AASR
MAX5022EUA75%-40°C to +85°C 8 μMAX—
MAX5022EPA75%-40°C to +85°C 8 PDIP—
WARNING: The MAX5021/MAX5022 are designed to work
with high voltages. Exercise caution!
MAX5021/MAX5022
Current-Mode PWM Controllers for Isolated
Power Supplies
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN= +11V to +28V, VCS= 0, OPTO is unconnected, 10nF bypass capacitors at VINand VCC, NDRV unconnected, TA= -40°C to
+85°C, unless otherwise noted. Typical values are at VIN= +12V, TA= +25°C, unless otherwise noted.) (Note 1)
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.
VINto GND.............................................................-0.3V to +30V
VCCto GND............................................................-0.3V to +13V
NDRV to GND.............................................-0.3V to (VCC+ 0.3V)
CS, OPTO to GND....................................................-0.3V to +6V
NDRV Short-Circuit to GND........................................Continuous
Continuous Power Dissipation (TA= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C).............696mW
8-Pin µMAX (derate 4.5mW/°C above +70°C)..............362mW
8-Pin PDIP (derate 9.1mW/°C above +70°C)................727mW
Operating Temperature Range...........................-40°C to +85°C
Storage Temperature Range.............................-55°C to +150°C
Lead Temperature (soldering 10s)..................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
UNDERVOLTAGE LOCKOUT/STARTUP
Undervoltage Lockout Wakeup
LevelVUVRVIN rising222426V
Undervoltage Lockout Shutdown
LevelVUVFVIN falling9.31010.9V
VIN Supply Current at StartupISTARTVIN = +22V5085µA
VIN RangeVIN1128V
TUVRVIN steps up from +9V to +26V5Undervoltage Lockout
Propagation DelayTUVFVIN steps down from +26V to +9V1µs
INTERNAL SUPPLY
VCC Regulator Set PointVCCSPVIN = +11V to +28V, sourcing 1µA to 5mA
from VCC7.010.5V
VIN = +28V, OPTO connected to GND0.92.43VIN Supply Current after StartupIINVIN = +28V, OPTO unconnected (Note 2)0.4mA
GATE DRIVER
RON(LOW)Measured at NDRV sinking 5mA1020Driver Output ImpedanceRON(HIGH)Measured at NDRV sourcing 5mA2040 Ω
Driver Peak Sink CurrentISINK250mA
Driver Peak Source CurrentISOURCE150mA
PWM COMPARATOR
Comparator Offset VoltageVOPWMVOPTO - VCS600750900mV
CS Input Bias CurrentICS-2+2µA
Propagation Delay from
Comparator Input to NDRVTPWM25mV overdrive60ns
Minimum On-TimeTON(MIN)150ns
CURRENT-LIMIT COMPARATOR
Current-Limit Trip ThresholdVCS540600660mV
Current-Limit Propagation Delay
from Comparator Input to NDRVTCL25mV overdrive60ns
MAX5021/MAX5022
Current-Mode PWM Controllers for Isolated
Power Supplies
ELECTRICAL CHARACTERISTICS (continued)
(VIN= +11V to +28V, VCS= 0, OPTO is unconnected, 10nF bypass capacitors at VINand VCC, NDRV unconnected, TA= -40°C to
+85°C, unless otherwise noted. Typical values are at VIN= +12V, TA= +25°C, unless otherwise noted.) (Note 1)
Note 1:All devices are 100% tested at TA= +25°C. All limits over temperature are guaranteed by characterization.
Note 2:This minimum current after startup is a safeguard that prevents the VINpin voltage from rising in the event
that OPTO and NDRV become unconnected.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
OSCILLATOR
Switching FrequencyfSW230262290kHz
MAX50215051Maximum Duty CycleDMAXMAX50227576%
OPTO INPUT
OPTO Pullup VoltageVOPTOOPTO sourcing 10µA5.5V
OPTO Pullup ResistanceROPTO4.56.27.9kΩ
Typical Operating Characteristics
(VIN= 15V, TA = +25°C, unless otherwise noted.)
UNDERVOLTAGE LOCKOUT
vs. TEMPERATURE
MAX5021/22 toc01
TEMPERATURE (°C)
UNDERVOLTAGE LOCKOUT (V)
VIN RISING
UNDERVOLTAGE LOCKOUT
vs. TEMPERATURE
MAX5021/22 toc02
TEMPERATURE (°C)
UNDERVOLTAGE LOCKOUT (V)
VIN FALLING
STARTUP CURRENT
vs. TEMPERATURE
MAX5021/22 toc03
TEMPERATURE (°C)
STARTUP CURRENT (
VIN = 23.0V
MAX5021/MAX5022
Current-Mode PWM Controllers for Isolated
Power Supplies
Typical Operating Characteristics (continued)
(VIN= 15V, TA = +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. TEMPERATURE
MAX5021/22 toc04
TEMPERATURE (°C)
SUPPLY CURRENT (mA)
VIN = 28.0V
VOPTO = VCS = 0
MAXIMUM VCC
vs. TEMPERATURE
MAX5021/22 toc05
TEMPERATURE (°C)
MAXIMUM V
(V)
VIN = 28.0V
VCS = 0
OPTO = UNCONNECTED
MINIMUM VCC
vs. TEMPERATURE
MAX5021/22 toc06
TEMPERATURE (°C)
MINIMUM V
(V)
VIN = 10.8V
5mA LOAD ON VCC
VCS = 0
OPTO = UNCONNECTED
CURRENT SENSE THRESHOLD
vs. TEMPERATURE
MAX5021/22 toc07
TEMPERATURE (°C)
CURRENT SENSE THRESHOLD (mV)
+3σ
-3σ
MEAN
TOTAL NUMBER OF
DEVICES = 500
CURRENT SENSE
THRESHOLD
MAX5021/22 toc08
CURRENT SENSE THRESHOLD (mV)
FREQUENCY (%)
TOTAL NUMBER
OF DEVICES = 200
OSCILLATOR FREQUENCY
vs. TEMPERATURE
MAX5021/22 toc09
TEMPERATURE (°C)
OSCILLATOR FREQUENCY (kHz)
TOTAL NUMBER
OF DEVICES = 50
+3σ
-3σ
MEAN
OSCILLATOR FREQUENCY
MAX5021/22 toc10
OSCILLATOR FREQUENCY (kHz)
FREQUENCY (%)
TOTAL NUMBER
OF DEVICES = 200
CURRENT SENSE DELAY
vs. TEMPERATURE
MAX5021/22 toc11
TEMPERATURE (°C)
CURRENT SENSE DELAY (ns)
UNDERVOLTAGE LOCKOUT
DELAY vs. TEMPERATURE
MAX5021/22 toc12
TEMPERATURE (°C)
UNDERVOLTAGE LOCKOUT DELAY (
VIN RISING
VIN FALLING
Detailed Description
The MAX5021/MAX5022 are current-mode PWM con-
trollers that have been specifically designed for use in
isolated power supplies. An undervoltage lockout cir-
cuit (UVLO) with a large hysteresis (14V) along with
very low startup and operating current result in high-
efficiency, universal input power supplies. Both devices
can be used in power supplies capable of operating
from a universal 85VAC to 265VAC line or the telecom
voltage range of -36VDC to -72VDC.
Power supplies designed with these devices use a
high-value startup resistor, RS, (series combination ofand R2) that charges a reservoir capacitor, C2 (see
Figure 1). During this initial period while the voltage is
less than the UVLO start threshold, the IC typically con-
sumes only 50µA of quiescent current. This low startup
current and the large UVLO hysteresis combined with
the use of a ceramic capacitor C2 keeps the power dis-
sipation in RSto less than 1/4W even at the high end of
the universal AC input voltage (265VAC).
The MAX5021/MAX5022 include a cycle-by-cycle cur-
rent limit which turns off the gate drive to the external
MOSFET during an overcurrent condition. If the output
on the secondary side of transformer T1 is shorted, the
tertiary winding voltage will drop below the 10V thresh-
old causing the UVLO circuit to turn off the gate drive to
the external power MOSFET, thus re-initiating the start-
up sequence.
Startup
Figure 2 shows the voltages on VINand VCCduring
startup. Initially, both VINand VCCare 0V. After the line
voltage is applied, C2 charges through the startup
resistor, RS, to an intermediate voltage at which point
the internal reference and regulator begin charging C3
(see Figure 1). The bias current consumed by the
device during this period is only 50µA; the remaining
input current charges C2 and C3. Charging of C3 stops
when the VCCvoltage reaches approximately 9.5V,
while the voltage across C2 continues rising until it
reaches the wakeup level of 24V. Once VINexceeds
the UVLO threshold, NDRV begins switching the
MOSFET, transferring energy to the secondary and ter-
tiary outputs. If the voltage on the tertiary output builds
to higher than 10V (UVLO lower threshold), then startup
has been accomplished and sustained operation
will commence.
If VINdrops below 10V before startup is complete, then
the IC goes back into UVLO. In this case, increase the
value of C2 and/or use a MOSFET with a lower gate-
charge requirement.
Startup Time Considerations
The VINbypass capacitor C2 supplies current immediate-
ly after wakeup. The size of C2 will determine the number
of cycles available for startup. Large values for C2 will
increase the startup time, but will also supply more gate
charge, allowing for more cycles after wakeup. If the
value of C2 is too small, VINwill drop below 10V because
MAX5021/MAX5022
Current-Mode PWM Controllers for Isolated
Power Supplies
Pin Description
PIN
SOT23PDIP
μMAX
NAMEFUNCTIONCSC ur r ent S ense C onnecti on for P WM Reg ul ati on and Over cur r ent P r otecti on. The cur r ent- l i m i t
com p ar ator thr eshol d i s i nter nal l y set to 0.6V .7GNDPower-Supply Ground6NDRVExternal N-Channel MOSFET Gate ConnectionVCCGate Drive Supply. Internally regulated down from VIN. Decouple with a 10nF or larger
capacitor to GND.VIN
IC Supply. Decouple with a 10nF or larger capacitor to GND. Connect a startup resistor
(Rs) from the input supply line to VIN. Connect to bias winding through diode rectifier.
See Typical Operating Circuit.1OPTOOptocoupler Transistor Collector Connection. Connect emitter of optocoupler to GND.
The OPTO has an internal pullup resistor with a typical value of 6.2kΩ.4, 5N.C.No Connection. Do not make connections to these pins.
MAX5021/MAX5022
NDRV did not switch enough times to build up sufficient
voltage across the tertiary output to power the device.
The device will go back into UVLO and will not start. Use
a low-leakage ceramic or film capacitor for C2 and C3.
As a rule of thumb, off-line power supplies keep typical
startup times to less than 500ms even in low-line condi-
tions (85VAC input). Size the startup resistor, RS, to sup-
ply the maximum startup bias of the IC (85µA) plus the
additional current required for charging the capacitors
C2 and C3 in less than 500ms. This resistor dissipates
continuous power in normal operation, despite the fact
that it is only used during the startup sequence.
Therefore it must be chosen to provide enough current
for the low-line condition as well as have an appropriate
power rating for the high-line condition (265VAC). In
most cases, split the value into two resistors connected
in series for the required voltage of approximately
400VDC.
The typical value for C2 and C3 is 220nF. The startup
resistor, RS, provides both the maximum quiescent cur-
rent of 85µA and the charging current for C2 and C3.
Bypass capacitor C3 charges to 9.5V and C2 charges
to 24V all within the desired time period of 500ms, for
an overall average charging current of 15µA. Hence,
the startup resistor must provide a total of at least
100µA. Developing 100µA from an input voltage of
Current-Mode PWM Controllers for Isolated
Power SuppliesAC
CENTRAL SEMICONDUCTOR
CBR1-D100S
470μH
MAX5022
OPTO
FAIRCHILD
CNY17-3
OPTO
NOTE: ALL RESISTORS ARE 5% UNLESS OTHERWISE SPECIFIED.
CTX03-15256
3A, 40V
ON SEMICONDUCTOR
MBRS340T3
10Ω
150μF
6.3V
1000pF
0.1μF
10μF
400V
10μF
400VR3
1kΩ
24.9kΩ
R10
10Ω
480μH, 60TR1
360kΩR8
1.2kΩ
360kΩR11
10Ω
+5V OUT
0.01μF
8200pF
0.22μF
INTERNATIONAL RECTIFIER
IRFRC20
0.22μF
85VAC TO
265VAC IN
250mA, 75V
CENTRAL SEMICONDUCTOR
CMPD914
8.06kΩ
RCS
1.78Ω
240kΩ
TEXAS
INSTRUMENTS
TLV431AIDBV
OPTONDRV
VCCVIN
GND
RS = R1 + R2
Figure 1. Universal 5W Off-Line Standby Power Supply
TIME (ms)
, V
(V)
VCC
VIN10050150200
VCC DROPS SLIGHTLY WHEN
NDRV BEGINS SWITCHING
IC COMES OUT OF UVLO
(WAKEUP)
VIN SUPPLIED BY TERTIARY
WINDING (NORMAL OPERATION)
VCC BYPASS CAPACITOR
FULLY CHARGED
VIN SUPPLIED BY C2
Figure 2. VINand VCCDuring Startup

Partno	Mfg	Dc	Qty	Available	Descript
MAX5021EUT+T	MAXIM	N/a	100	avai	Current-Mode PWM Controllers for Isolated Power Supplies