MAX8515AEZK+T ,Wide-Input 0.6V Shunt Regulators for Isolated DC-DC ConvertersApplicationsIsolated DC-to-DC Converters Network, Telecom, and Cellular Base StationPower SuppliesT ..
MAX8515EXK-T ,Wide-Input 0.6V Shunt Regulators for Isolated DC-to-DC ConvertersApplicationsIsolated DC-to-DC Converters Network, Telecom, and Cellular Base StationPower SuppliesT ..
MAX8516EUB ,1.425V to 3.6V Input, 1A, 0.2V Dropout LDO Regulatorsfeatures a 150ms power-on reset output.Typical Operating Circuit®The parts are packaged in a 10-pin ..
MAX8516EUB+ ,1.425V to 3.6V Input, 1A, 0.2V Dropout LDO RegulatorsFeaturesThe MAX8516/MAX8517/MAX8518 low-dropout linear ● 1.425V to 3.6V Input Voltage Rangeregulato ..
MAX8516EUB+ ,1.425V to 3.6V Input, 1A, 0.2V Dropout LDO RegulatorsApplicationsMAX8516MAX8517● Servers ● Post RegulatorsMAX8518● Storage ● NotebooksPOWER-ON RESET4.7µ ..
MAX8516EUB+ ,1.425V to 3.6V Input, 1A, 0.2V Dropout LDO RegulatorsApplicationsMAX8516MAX8517● Servers ● Post RegulatorsMAX8518● Storage ● NotebooksPOWER-ON RESET4.7µ ..
MB81C81A-35 ,CMOS 256K-BIT HIGH-SPEED SRAMMay 1990 00
Edition1.0 FUJITSU
M38 1 C8 1A-25/-35
CMOS 256K-BI T HIGH-SPEED SRAM
256K Words ..
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMFUJITSU SEMICONDUCTORADVANCED INFO. AE0.1EDATA SHEETMEMORYCMOS4 · 512 K · 32 BITSYNCHRONOUS DYNAMIC ..
MB81F643242C-10FN ,4 x 512K x 32 bit synchronous dynamic RAMfeatures a fully synchronous operation referenced to a positive edge clock whereby all operations a ..
MB81N643289-60FN ,8 x 256K x 32 bit double data rate FCRAMapplications where large memory density and high effective bandwidth arerequired and where a simple ..
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MB8264A-10 , MOS 65536-BIT DYNAMIC RANDOM ACCESS MEMORY
MAX8515AEZK+T
Wide-Input 0.6V Shunt Regulators for Isolated DC-DC Converters
General DescriptionThe MAX8515A/MAX8515 shunt regulators simplify the
design of voltage regulation and overvoltage protection
(OVP) functions in high-accuracy isolated DC-to-DC con-
verters with output voltages as low as 0.6V. The devices
have supply voltage and feedback inputs separated from
the output shunt stage, and can operate directly from the
DC-to-DC converter output stage when the output voltage
is 1.8V to 18V. Alternately, the MAX8515A/MAX8515 input
stage can be biased from an unregulated 1.7V to 28V
supply, independent of DC-to-DC converter output volt-
age. The MAX8515A/MAX8515 shunts 20mA when the
output voltage is as low as 0.2V.
The MAX8515A features an initial output accuracy of
0.5% at +25°C and 1% from -40°C to +85°C and provides
the output voltage regulation function for isolated DC-to-
DC converters. The MAX8515 features initial output
accuracy of 1% at +25°C and 1.8% from -40°C to +85°C
and can provide an output OVP function for isolated DC-
to-DC converters. High open-loop bandwidth allows
design of high-bandwidth DC-to-DC converters.
Low-cost, low-dropout linear regulators can be designed
with the MAX8515A/MAX8515 and an external NPN tran-
sistor for cost-conscious applications that do not require
overcurrent, short-circuit, or overtemperature protection.
The MAX8515/MAX8515A are available in space-saving
5-pin SC70 and SOT23 packages and are specified over
the -40°C to +85°C extended temperature range. An eval-
uation kit is available to speed designs.
ApplicationsIsolated DC-to-DC Converters
Network, Telecom, and Cellular Base Station
Power Supplies
Low-Dropout Linear Regulators
Shunt Regulator
Adjustable Voltage Reference
FeaturesMAX8515A
0.6V ±0.5% Initial Accuracy at +25°C
0.6V ±1% Accuracy from -40°C to +85°CMAX8515
0.6V ±1% Initial Accuracy at +25°C
0.6V ±1.8% Accuracy from -40°C to +85°CSinks 20mA at 0.2V to 18VInput Voltage Range from 1.7V to 28VDirectly Drives Optocouplers0.2ΩDynamic Output ImpedanceSpace-Saving 5-Pin SC70 or SOT23 Packages
MAX8515A/MAX8515
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC Converters19-2528; Rev 1; 2/03
Ordering Information
PARTTEMP RANGEPIN-PACKAGE
MAX8515AEXK-T-40°C to +85°C5 SC70-5
MAX8515AEZK-T-40°C to +85°C5 Thin SOT23-5
MAX8515EXK-T-40°C to +85°C5 SC70-5
MAX8515EZK-T-40°C to +85°C5 Thin SOT23-5
GNDOUTFBPGND
MAX8515A
MAX8515
SC7O/THIN SOT23TOP VIEW
Pin ConfigurationMAX8515A
MAX8515
PRIMARY SIDE
PWM CONVERTER
INPUT SUPPLY
1.7V TO 28V
INPUT
1.7V TO 18V
ISOLATED DC-DC
CONVERTER
OUTPUT
(DOWN TO 0.6V)
OUTGND
PGND
CONTROL
VOLTAGE
ypical Operating Circuit
5-PIN
SC700mmx2.1
EVALUATION KIT
AVAILABLE
Functional Diagram appears at end of data sheet.
Selector Guide appears at end of data sheet.
MAX8515A/MAX8515
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC Converters
ABSOLUTE MAXIMUM RATINGSStresses 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.
IN to GND...............................................................-0.3V to +30V
OUT to GND...........................................................-0.3V to +20V
FB to GND.................-0.3V to the lower of 5.5V and (VIN+0.3V)
PGND to GND.......................................................-0.3V to +0.3V
Continuous Power Dissipation (TA =+70°C)
5-Pin SC70 (derate 3.1mW/°C above +70°C)...........246.9mW
5-Pin Thin SOT23 (derate 9.1mW/°C above +70°C)....727mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature Range............................-40°C to +150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
ELECTRICAL CHARACTERISTICS(VIN = 3.3V, OUT = FB, IOUT = 5mA, TA = -40°C to +85°C, unless otherwise noted. Typical values are at TA = +25°C.) (Note 1)
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITSIN Voltage RangeVIN1.728V
IOUT = 0.3mA0.51IN Supply CurrentIINVIN = 2V to 28VIOUT = 10mA2.54mA
MAX8515AE_K0.5970.60.603TA = +25°CMAX8515E_K0.5940.60.606
MAX8515AE_K0.5950.60.605TA = 0°C to +85°CMAX8515E_K0.5920.60.608
MAX8515AE_K0.5940.60.606
FB Threshold Accuracy
TA = -40°C to +85°CMAX8515E_K0.5890.60.608
FB Load RegulationIOUT = 1mA to 20mA3.86mV
VIN = 2V to 28V0.21FB Line RegulationVIN = 1.7V to 28V1.5mV
FB Output Voltage RegulationVOUT = 0.2V to 18V, IOUT = 1mA0.21mV
FB Input Bias CurrentIFB(BIAS)VIN = 28V-0.10.02+0.1µA
OUTOUT Voltage RangeVOUT0.218V
Maximum Output CurrentIOUT(MAX)VOUT = 0.2V, VIN = 2V, VFB = 0.63V20mA
TA = +25°C0.0010.1Output Leakage CurrentIOUT(LEAK)VIN = 28V, VOUT = 18V,
VFB = 0VTA = +85°C0.03µA
Dynamic Output ImpedanceZOUTIOUT = 1mA to 20mA, f <1kHz0.20.32Ω
Note 1:Devices are production tested at TA = +25°C, limits over temperature are guaranteed by design.
MAX8515A/MAX8515
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC ConvertersFB BIAS CURRENT (nA)
FB BIAS CURRENT
vs. TEMPERATURE
MAX8515 toc01
TEMPERATURE (°C)35-1510-4085
VIN = 3.3V
VIN = 10V
VIN = 28V
OUT-LEAKAGE CURRENT (nA)
OUT-LEAKAGE CURRENT
vs. TEMPERATUREMAX8515 toc02
TEMPERATURE (°C)35-1510-4085
VIN = 28V
VOUT = 18V
FB = GND70
GAIN AND PHASE vs. FREQUENCY
VOUT = 0.6V
MAX8515 toc03
FREQUENCY (kHz)
GAIN (dB)
PHASE (DEGREES)10
FIGURE 2
GAIN AND PHASE vs. FREQUENCY
VOUT = 6VMAX8515 toc04
FREQUENCY (kHz)
GAIN (dB)
FIGURE 2
PHASE (DEGREES)
OUTPUT VOLTAGE SLEW RATEMAX8515 toc05
2μs/div
0.55V
0.66V
VOUT: 2V/div
VFB: 200mV/div
C2 = OPEN
SUPPLY CURRENT vs. LOAD CURRENTMAX8515 toc07
LOAD CURRENT (mA)
SUPPLY CURRENT (mA)105
VIN = 28V
VIN = 10V
VIN = 3.3V
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCYMAX8515 toc06
FREQUENCY (Hz)
PSRR (dB)100101
0.110k
TA = +25°C
TA = -40°C
TA = +25°C
TA = +85°C
Typical Operating Characteristics(VIN= 3.3V, IOUT = 5mA, FB = OUT, circuit in Figure 1, C1 = 0.1µF, C2 = 1µF, TA = +25°C, unless otherwise specified.)
MAX8515A/MAX8515
Detailed DescriptionThe MAX8515A/MAX8515 adjustable shunt regulators
feature isolated supply inputs and outputs, ideal for isolat-
ed power-supply applications using an optocoupler in the
feedback path. The MAX8515A/MAX8515 sink 20mA with
VOUTat 0.2V. The wide input supply range allows the
device to operate from 1.7V to 28V. The MAX8515A/
MAX8515 compare the FB input to a precision 600mV
reference. If the FB input is low, OUT sinks no current. If
FB rises above 600mV, OUT sinks up to 20mA.
Applications Information
Shunt Regulator/Adjustable
Voltage ReferenceFigure 1 shows the MAX8515A/MAX8515 configured as a
shunt regulator. Connect FB to OUT for an output voltage
of 0.6V. Connect a 1.0µF capacitor from OUT to GND
when the output voltage is 0.6V. A resistor-divider con-
nected from OUT to GND produces higher output volt-
ages and allows for a smaller output capacitor. The
value of the output capacitor is inversely proportional to
the output voltage:
Set the current limit with a resistor connected from IN to
OUT. This type of shunt regulator is limited to low-current
applications. The MAX8515A/MAX8515 can typically sink
up to 20mA in this application.
Figure 2 shows the test circuits for gain and phase plots.R1V
OUT
OUT
OUT+106μF
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC Converters
Typical Operating Characteristics (continued)(VIN= 3.3V, IOUT= 5mA, FB = OUT, circuit in Figure 1, C1 = 0.1µF, C2 = 1µF, TA = +25°C, unless otherwise specified.)
OUTPUT VOLTAGE CHANGE
vs. LOAD CURRENTMAX8515 toc08
LOAD CURRENT (mA)
OUTPUT VOLTAGE CHANGE (%)105
OUTPUT VOLTAGE CHANGE (%)0
OUTPUT VOLTAGE CHANGE
vs. INPUT VOLTAGE
MAX8515 toc09
INPUT VOLTAGE (V)18813328
PINNAMEFUNCTIONPGNDPower Ground. Connect PGND and GND together.GNDAnalog Ground. Connect GND and PGND together.OUTOutput. Connect a ceramic capacitor from OUT to GND. See the Applications Information section.INSupply Input. Connect a 0.1µF capacitor to GND.FBFeedback Input. Regulates to 600mV.
Pin Description
Optical Feedback
Setting VOUTFigure 3 displays an application circuit using the
MAX8515A/MAX8515 in an opto-isolated feedback cir-
cuit. The maximum bias current for the photodiode is
set with R1. The isolated DC-to-DC converter compen-
sation circuit is formed with R2, C3, and C4. Resistors
R3 and R4 set the isolated DC-to-DC converter output
voltage. C1 decouples the input supply and C2 is
needed to stabilize the MAX8515A/MAX8515. Calculate
VREG with the following equation:
Set R4 to 10kΩand calculate R3 by:
For example, given a regulator output voltage of 1.8V
and R4 = 10kΩ, R3 is found to be 20kΩ.
Compensation CircuitA typical compensation scheme is depicted in Figure 3.
C3 provides an integrator function that minimizes out-
put regulation error.
R2 provides additional phase compensation at the zero
frequency fz:
The midband gain is given by:
Add C4 for high-frequency noise rejection. Determine
R2 based on the midband gain required by the isolated
power supply. Choose fzbased on the power supply
small-signal transfer function. Calculate C3 once fz
is known.R=2Z2R2C3=××V-OUT=×14 RR3REG=×+061.
MAX8515A/MAX8515
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC ConvertersFigure 1. MAX8515A/MAX8515 Typical Application Circuit,
Shunt Regulator/Adjustable Voltage Reference
MAX8515A
MAX8515
0.1μF
OUTGND
VIN
1.8V
VOUT
0.6V/20mA
R1 = SHORT
R2 = OPEN
1.0μFR1
PGNDVIN (V)
R3 (Ω)
1.33k
Figure 2. Test Circuits for Gain and Phase Plots
MAX8515A
MAX8515
0.1μF
OUTGND
3.3V
5.6V
GAIN = TEST/REFERENCE
NETWORK
ANALYZER
SOURCE
0.82μF
50kΩ
1kΩ
VOUT = 0.6V
TEST CIRCUIT
1MΩ
1MΩ
2.2nF
2.2nF
TEST
PGND
MAX8515A
MAX8515
0.1μF
OUTGND
3.3V
11V
GAIN = TEST/REFERENCE
REFERENCE
REFERENCE
NETWORK
ANALYZER
SOURCE
50kΩ
115kΩ
VOUT = 6V
TEST CIRCUIT
1MΩ
0.1μF
10kΩ
90.1kΩ
1MΩ
160kΩ
2.2nF
2.2nF
TEST
PGND
MAX8515A/MAX8515
Overvoltage ProtectionFigure 4 shows an isolated OVP circuit. R1 limits the
current supplied to the photodiode. R2 limits the
MAX8515A/MAX8515 input current. R3 and R4 set the
trip threshold for the OVP. C1 is the input supply
decoupling capacitor.
Values for R3 and R4 are chosen based on the needed
OVP threshold. For example, a trip threshold of 25%
above the rated output voltage is needed for an OVP
circuit. The values of R3 can be determined from the
following equation once R4 is chosen; 10kΩis recom-
mended for R4. Then, R3 = 6.2kΩ.
where VOVP= 0.8V x 1.25 for the given example.
Linear RegulatorUse an external pass transistor in conjunction with the
MAX8515A/MAX8515 to create a linear regulator as
shown in Figure 5. Determine the output voltage of the
regulator by:
Choose R1 to maintain load regulation up to a 2A load.
Use the following equation:
where IO_MAXis the rated maximum output current,
which is 2A in this application circuit. VREGis the output
voltage of the linear regulator. VBEis the base-to-emitter
forward voltage of Q1, and βis the minimum current gain
of Q1 at rated load current. VINis the minimum input volt-
age at IN. For the typical application circuit, VIN_MIN=
2.375V, VREG= 1.0V, VBE= 0.65V, and β= 180. Choose
R1 = 15Ωfor fast transient response. C1 is the input
decoupling capacitor and C2 is the compensation
capacitor. Use a 1µF, 6.3V capacitor for this application.
Figure 6 shows a typical load-regulation curve for the cir-
cuit in Figure 5. This circuit does not provide short-circuit,
overcurrent, or overtemperature protection. V-V-V
IN_MINREGBE
O_MAX=×βR2REG=×+061.VV-OVP=×14R
Wide-Input 0.6V Shunt Regulators for
Isolated DC-to-DC ConvertersFigure 4. MAX8515A/MAX8515 Typical Application Circuit,
OVP Circuit (Set to 1V OVP Threshold for 0.8V Nominal Output)
MAX8515A
MAX8515
OUT
0.8V
DC-DC OUTPUT
6V TO 10V
0.1μF
16V
6.2kΩ
10kΩ
1.2kΩ
2kΩ
GND
PGND
FEEDBACK
OPTOCOUPLER
Figure 3. MAX8515A/MAX8515 Typical Application Circuit,
Opto-Feedback Circuit
MAX8515A
MAX8515
OUT
0.1μF
VREG
1.8V
0.1μF
20kΩ
10kΩ
47kΩ
GND
PGND
MAX5003
CONPGND
NDRV
INPUT
SUPPLY
