MAX5019CSA ,Current-mode PWM controller with integrated startup circuitELECTRICAL CHARACTERISTICS(V = 13V, a 10µF capacitor connects V to GND, V = 0, V+ = 48V, 0.1µF capa ..
MAX5019CSA+ ,Current-Mode PWM Controllers with Integrated Startup CircuitApplicationsMAX5020ESA* -40°C to +85°C8-SO*See Selector Guide at end of data sheet.Telecom Power Su ..
MAX5019ESA ,Current-Mode PWM Controllers with Integrated Startup CircuitMAX5019/MAX502019-2115; Rev 0; 7/01Current-Mode PWM Controllers with IntegratedStartup Circuit
MAX5019ESA+ ,Current-Mode PWM Controllers with Integrated Startup CircuitELECTRICAL CHARACTERISTICS(V = 13V, a 10µF capacitor connects V to GND, V = 0, V+ = 48V, 0.1µF capa ..
MAX5019ESA+T ,Current-Mode PWM Controllers with Integrated Startup CircuitELECTRICAL CHARACTERISTICS(V = 13V, a 10µF capacitor connects V to GND, V = 0, V+ = 48V, 0.1µF capa ..
MAX5020CSA ,Current-mode PWM controller with integrated startup circuitFeaturesThe MAX5019/MAX5020 integrate all the building Wide Input Range: (18V to 110V) or (13V to ..
MAX9175EUB ,670MHz LVDS-to-LVDS and Anything-to-LVDS 1:2 Splittersfeatures a fail-safe circuit that dri-♦ Low-Power CMOS Designves the outputs high when the input is ..
MAX9175EUB+ ,670MHz LVDS-to-LVDS and Anything-to-LVDS 1:2 SplittersELECTRICAL CHARACTERISTICS(V = +3.0V to +3.6V, R = 100Ω ±1%, PD_ = high, differential input voltage ..
MAX9176EUB ,670MHz LVDS-to-LVDS and Anything-to-LVDS 2:1 MultiplexersApplications Ordering InformationProtection SwitchingPART TEMP RANGE PIN-PACKAGELoopbackMAX9176EUB ..
MAX9176EUB+T ,670MHz, LVDS-to-LVDS and Anything-to-LVDS, 2:1 MultiplexersELECTRICAL CHARACTERISTICS(V = 3.0V to 3.6V, R = 100Ω, PD = high, SEL = high or low, differential i ..
MAX9177EUB+T ,670MHz, LVDS-to-LVDS and Anything-to-LVDS, 2:1 MultiplexersFeaturesThe MAX9176/MAX9177 are 670MHz, low-jitter, low-♦ 1.0ps Jitter (max) at 670MHz (RMS)skew 2: ..
MAX9179EUE ,Quad LVDS Receiver with HysteresisApplicationsLaser PrintersOrdering InformationDigital CopiersPART TEMP RANGE PIN-PACKAGECell-Phone ..
MAX5019CSA-MAX5020CSA
Current-mode PWM controller with integrated startup circuit
General DescriptionThe MAX5019/MAX5020 integrate all the building
blocks necessary for implementing DC-DC fixed-fre-
quency power supplies. Either primary- or secondary-
side regulation may be used to implement isolated or
nonisolated power supplies. These devices are current-
mode controllers with an integrated high-voltage start-
up circuit suitable for telecom/industrial voltage range
power supplies. Current-mode control with leading-
edge blanking simplifies control-loop design and inter-
nal ramp compensation circuitry stabilizes the current
loop when operating at duty cycles above 50%
(MAX5019). The MAX5019 allows 85% operating duty
cycle and can be used to implement flyback converters
whereas the MAX5020 limits the operating duty cycle to
less than 50% and can be used in single-ended for-
ward converters. A high-voltage startup circuit allows
these devices to draw power directly from the 18V to
110V input supply during startup. The switching fre-
quency is internally trimmed to 275kHz ±10%, thus
reducing magnetics and filter component costs.
The MAX5019/MAX5020 are available in 8-pin SO
packages.
Warning: The MAX5019/MAX5020 operate with highvoltages. Exercise caution.
ApplicationsTelecom Power Supplies
Industrial Power Supplies
Networking Power Supplies
Isolated Power Supplies
FeaturesWide Input Range: (18V to 110V) or (13V to 36V)Isolated (without optocoupler) or Nonisolated
Power SupplyCurrent-Mode ControlLeading-Edge BlankingInternally Trimmed 275kHz ±10% OscillatorLow External Component CountSoft-StartHigh-Voltage Startup CircuitPulse-by-Pulse Current LimitingThermal ShutdownSO-8 Package
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup Circuit
Pin Configuration
Ordering Information
Typical Operating Circuit19-2115; Rev 0; 7/01
*See Selector Guide at end of data sheet.
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup Circuit
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS(VDD= 13V, a 10µF capacitor connects VCCto GND, VCS= 0, V+ = 48V, 0.1µF capacitor connected from SS_SHDNto GND, NDRV
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.
V+ to GND……………………………………...……-0.3V to +120V
VDDto GND.………………………………….……….-0.3V to +40V
VCCto GND.………………….……………………-0.3V to +12.5V
FB, NDRV, SS_SHDN, CS to GND .……-0.3V to VCC+ 0.3V
VDDand VCCCurrent …………………...…………………..20mA
NDRV Current Continuous...………………………………….25mA
NDRV Current for Less than 1µs..………….…………….……±1A
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C).………....471mW
Operating Temperature Range…………..……...-40°C to +85°C
Storage Temperature Range……………..…….-65°C to +150°C
Lead Temperature (soldering, 10s) ………………………+300°C
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup Circuit
ELECTRICAL CHARACTERISTICS (continued)(VDD= 13V, a 10µF capacitor connects VCCto GND, VCS= 0, V+ = 48V, 0.1µF capacitor connected from SS_SHDNto GND, NDRV
Typical Operating Characteristics(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup CircuitMAX5020
MAXIMUM DUTY CYCLE
vs. TEMPERATURE
MAX5019 toc04
TEMPERATURE (°C)
MAXIMUM DUTY CYCLE (%)
V+ SUPPLY CURRENT
vs. TEMPERATUREMAX5019 toc05
V+ SUPPLY CURRENT (mA)
TEMPERATURE (°C)
SOFT-START SOURCE CURRENT
vs. TEMPERATURE
MAX5019 toc06
TEMPERATURE (°C)
SOFT-START SOURCE CURRENT (
V+ INPUT CURRENT vs.
TEMPERATURE (AFTER STARTUP)
MAX5019 toc07
TEMPERATURE (°C)
V+ INPUT CURRENT (
V+ SHUTDOWN CURRENT
vs. TEMPERATURE
MAX5019 toc08
TEMPERATURE (°C)
V+ SHUTDOWN CURRENT (
CS THRESHOLD VOLTAGE
vs. TEMPERATURE
MAX5019 toc09
TEMPERATURE (°C)
CS THRESHOLD VOLTAGE (V)
NDRV RESISTANCE
vs. TEMPERATUREMAX5019 toc10
NDRV RESISTANCE (
TEMPERATURE (°C)
CURRENT-LIMIT DELAY
vs. TEMPERATURE
MAX5019 toc11
TEMPERATURE (°C)
CURRENT-LIMIT DELAY (ns)
VSS_SHDN vs. VDD
MAX5019
toc12
VDD (V)
SS_SHDN
(V)
Typical Operating Characteristics (continued)(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup Circuit
Typical Operating Characteristics (continued)(V+ = 48V, VDD= 13V, CS = GND, NRDV is open circuit, TA= +25°C, unless otherwise noted.)
MAX5019/MAX5020
Detailed DescriptionUse the MAX5019/MAX5020 PWM current-mode con-
trollers to design flyback- or forward-mode power sup-
plies. Current-mode operation simplifies control-loop
design while enhancing loop stability. An internal high-
voltage startup regulator allows the device to connect
directly to the input supply without an external startup
resistor. Current from the internal regulator starts the
controller. Once the tertiary winding voltage is estab-
lished the internal regulator is switched off and bias
current for running the IC is derived from the tertiary
winding. The internal oscillator is set to 275kHz and
trimmed to ±10%. This permits the use of small mag-
netic components to minimize board space. Both the
MAX5019 and MAX5020 can be used in power sup-
plies providing multiple output voltages. A functional
diagram of the IC is shown in Figure 1. Typical applica-
tions circuits for forward and flyback topologies are
shown in Figure 2 and Figure 3, respectively. For isolat-
ed flyback power supplies use the circuit of Figure 4.
Current-Mode ControlThe MAX5019/MAX5020 offer current-mode control
operation with added features such as leading-edge
blanking with dual internal path that only blanks the
sensed current signal applied to the input of the PWM
comparator. The current limit comparator monitors the
CS pin at all times and provides cycle-by-cycle current
limit without being blanked. The leading-edge blanking
of the CS signal prevents the PWM comparator from
prematurely terminating the on cycle. The CS signal
contains a leading-edge spike that is the result of the
MOSFET gate charge current, capacitive and diode
reverse recovery current of the power circuit. Since this
leading-edge spike is normally lower than the current
limit comparator threshold, current limiting is not
blanked and cycle-by-cycle current limiting is provided
under all conditions.
Use the MAX5019 in discontinuous flyback applications
where wide line voltage and load current variation is
expected. Use the MAX5020 for single transistor for-
ward converters where the maximum duty cycle must
be limited to less than 50%.
Under certain conditions it may be advantageous to
use a forward converter with greater than 50% duty
cycle. For those cases use the MAX5019. The large
duty cycle results in much lower operating primary
RMS currents through the MOSFET switch and in most
cases a smaller output filter inductor. The major disad-
Current-Mode PWM Controllers with Integrated
Startup Circuit
MAX5019/MAX5020
Current-Mode PWM Controllers with Integrated
Startup CircuitFigure 1. Functional Diagram
