MAX1967EUB+-MAX1967EUB+T Fast Delivery |IC PHOENIX CO.,LIMITED

MAX1967EUB+T ,Low-Cost Voltage-Mode PWM Step-Down ControllersELECTRICAL CHARACTERISTICS(VIN = VL = VCC = 5V (MAX1967), VIN = 5V (MAX1966), T = -40°C to +85°C (N ..
MAX1968EUI ,Power Drivers for Peltier TEC ModulesFeaturesThe MAX1968/MAX1969 are highly integrated and cost- Direct Current Control Prevents TEC Cu ..
MAX1968EVKIT ,Evaluation Kit for the MAX1968FeaturesThe MAX1968 evaluation kit (EV kit) is a fully assembled ±3A Output Currentand tested PC b ..
MAX196ACAI ,Multirange, Single %V, 12-Bit DAS with 12-Bit Bus InterfaceApplicationsMAX196D8 6 23 REFMAX198Industrial-Control SystemsD7 7 22 REFADJRoboticsD6 8 21 CH5Data- ..
MAX196ACAI+ ,6-Channel, Multirange, 5V, 12-Bit DAS with 12-Bit Bus Interface and Fault ProtectionFeatures♦ 12-Bit Resolution, 1/2LSB LinearityThe MAX196/MAX198 multirange, 12-bit data-acquisi-tion ..
MAX196ACAI+ ,6-Channel, Multirange, 5V, 12-Bit DAS with 12-Bit Bus Interface and Fault ProtectionFeatures♦ 12-Bit Resolution, 1/2LSB LinearityThe MAX196/MAX198 multirange, 12-bit data-acquisi-tion ..
MAX491MJD ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversELECTRICAL CHARACTERISTICS(V = 5V ±5%, T = T to T , unless otherwise noted.) (Notes 1, 2)CC A MIN M ..
MAX491MJD ,Low-Power / Slew-Rate-Limited RS-485/RS-422 TransceiversApplications ______________Ordering InformationLow-Power RS-485 TransceiversPART TEMP. RANGE PIN-PA ..
MAX4927ETN+ ,1000 Base-T, ±15kV ESD Protection LAN SwitchApplicationsSTMUX1000LNotebooks and Docking Stations ♦ Space-Saving Lead-Free PackageServers and Ro ..
MAX4928BETN+ ,DisplayPort/PCIe Passive SwitchesELECTRICAL CHARACTERISTICS(V = +3.3V ±10%, T =T to T , unless otherwise noted. Typical values are a ..
MAX4928BETN+T ,DisplayPort/PCIe Passive SwitchesApplicationsMAX4928BETN+ -40°C to +85°F 56 TQFN-EPDesktop PCs+Denotes a lead-free package/RoHS-Comp ..
MAX492CPA ,Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op AmpsELECTRICAL CHARACTERISTICS(V = 2.7V to 6V, V = GND, T = +25°C, unless otherwise noted.)CC EE APARAM ..

MAX1967EUB+-MAX1967EUB+T
Low-Cost Voltage-Mode PWM Step-Down Controllers
General Description
The MAX1966/MAX1967 are voltage-mode pulse-width-
modulated (PWM), step-down DC-DC controllers that
are ideal for a variety of cost-sensitive applications.
They drive low-cost N-MOSFETs for both the high-side
switch and synchronous rectifier and require no external
Schottky power diode or current-sense resistor. Short-
circuit and current-limit protection is provided by sens-
ing the drain-to-source voltage on the low-side FET.
Both devices can supply outputs as low as 0.8V and are
well suited for DSP cores and other low-voltage logic.
The MAX1966 has an input range of 2.7V to 5.5V while
the MAX1967 has an input range of 2.7V to 28V. In
ultra-low-cost designs, the MAX1966/MAX1967 can
provide efficiency exceeding 90% and can achieve
95% efficiency with optimized component selection.
The MAX1966/MAX1967 operate at 100kHz and ac-
commodate aluminum electrolytic capacitors and pow-
dered-iron core magnetics in minimum-cost designs.
They also provide excellent performance with high-per-
formance surface-mount components. The MAX1966 is
available in a low-cost 8-pin SO package. The MAX1967
is available in a 10-pin µMAX package.
Applications
FeaturesCost-Optimized DesignNo Schottky Diode or Current-Sense Resistor
Required>95% EfficiencyLow-Cost External ComponentsAll N-Channel FET Design2.7V to 5.5V Input Range (MAX1966)2.7V to 28V Input Range (MAX1967)0.8V Feedback for Low-Voltage Outputs100kHz Switching Frequency Accommodates
Low-Cost ComponentsThermal ShutdownOutput Current-Limit and Short-Circuit Protection
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
GNDVINCOMP/EN
BST
TOP VIEW
MAX1966
Pin Configurations
Ordering Information
MAX1966VOUT
2.7V TO
5.5V INPUT
VIN
COMP/EN
GND
BSTypical Operating Circuit
19-2286; Rev 1; 9/03
Pin Configurations continued at end of data sheet.
Set-Top Boxes
Graphic Card Supplies
xDSL Modems and
Routers
Cable Modems and
Routers
Telecom Power Supplies
Networking Power
Supplies
Termination Supplies
PARTTEMP RANGEPIN-PACKAGE
MAX1966ESA-40°C to +85°C8 SO
MAX1967EUB-40°C to +85°C10 µMAX
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = VL = VCC = 5V (MAX1967), VIN = 5V (MAX1966), TA= -40°C to +85°C (Note 1), unless otherwise noted. Typical values are at = +25°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.
(All Voltages Referenced to GND, Unless Otherwise Noted)
VIN to GND (MAX1966)............................................-0.3V to +6V
VIN to GND (MAX1967)..........................................-0.3V to +30V
VCC to GND (MAX1967)..........-0.3V, lower of 6V or (VIN+ 0.3V)
FB to GND................................................................-0.3V to +6V
DL, COMP/EN to GND (MAX1966)................-0.3V to VIN+ 0.3V
VL, DL, COMP/EN to GND (MAX1967).........-0.3V to VCC+ 0.3V
BST to LX..................................................................-0.3V to +6V
DH to LX........................................................-0.3V to BST + 0.3V
VL Short to GND (MAX1967)....................................................5s
RMS Input Current (any pin).............................................±50mA
Continuous Power Dissipation (TA= +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C)................471mW
10-Pin µMAX (derate 5.6mW/°C above +70°C)...........444mW
Operating Temperature Range...........................-40°C to +85°C
Junction Temperature......................................................+150°C
Storage Temperature Range.............................-65°C to +150°C
Lead Temperature (soldering, 10s).................................+300°C
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
MAX1967 VIN Operating Range4.928V
MAX1967 Operating Range with
VIN = VL2.75.5V
MAX1966 VIN Operating Range2.75.5V
MAX1967 VL Undervoltage
Lockout (UVLO) Trip LevelRising and falling edge, hysteresis = 2%2.352.532.66V
MAX1966 VIN UVLO
Trip LevelRising and falling edge, hysteresis = 2%2.352.532.66V
Operating Supply CurrentFB = 0.88V, no switching0.73mAL Outp ut V ol tag e ( M AX 1967 Onl y) 5.5V < VIN < 28V, 1mA < IVL < 25mA,
FB = 0.88V4.6755.3V
Thermal Shutdown (Note 1)Rising temperature, typical hysteresis = 10°C160°C
OSCILLATOR
0°C to +85°C82102124FrequencyfOSC-40°C to +85°C79102127kHz
Minimum Duty Cycle10%
Maximum Duty Cycle9095%
SOFT-START
Digital Ramp Period Internal 6-bit DAC for converter to ramp from
0 to full output voltage1024 /
fOSCs
Soft-Start LevelsVOUT /V
ERROR AMPLIFIER
2.7V < VCC < 5.5V, 0°C to +85°C0.7870.8000.815FB Regulation Voltage
(MAX1967)2.7V < VCC < 5.5V, -40°C to +85°C0.7820.8000.815V
2.7V < VIN < 5.5V, 0°C to +85°C0.7870.8000.815FB Regulation Voltage
(MAX1966)2.7V < VIN < 5.5V, -40°C to +85°C0.7820.8000.815V
FB to COMP/EN Gain4000V/V
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
ELECTRICAL CHARACTERISTICS (continued)
(VIN = VL = VCC = 5V (MAX1967), VIN = 5V (MAX1966), TA= -40°C to +85°C, unless otherwise noted. Typical values are at = +25°C.)
Note 1:Specifications to -40°C are guaranteed by design and not production tested.
Note 2:Thermal shutdown disables the buck regulator when the die reaches this temperature. Soft-start is reset and COMP/EN is
discharged to zero. In the MAX1967, the VL regulator remains on during thermal shutdown.
PARAMETERSYMBOLCONDITIONSMINTYPMAXUNITS
FB to COMP/EN
Transconductance-5µA < ICOMP/EN < 5µA70108160µS
FB Input Bias CurrentVFB = 0.880V3100nA
COMP/EN Source CurrentVCOMP/EN = 01546100µA
Current-Limit Threshold Voltage
(Across Low-Side NFET)LX to GND-340-305-270mV
MOSFET DRIVERS
Break-Before-Make Time30ns
DH On-Resistance in Low StateVBST = 5V, VLX = 0, IDH = -50mA1.64Ω
DH On-Resistance in High StateVBST = 5V, VLX = 0, IDH = 50mA2.55.5Ω
DH Peak Source and Sink
CurrentVBST = 5V, VLX = 0, DH = 2.5V1A
DL On-Resistance in Low StateIDL = -50mA1.12.5 Ω
DL On-Resistance in High StateIDL = 50mA2.55.5Ω
DL Source CurrentVDL = 2.5V1A
DL Sink CurrentVDL = 2.5V2A
Maximum Total (DH + DL)
Average Source CurrentVBST = 5V, VLX = 025mA
BST Leakage CurrentVBST = 33V, VLX = 28V050µA
LX Leakage CurrentVBST = 33V, VLX = 28V33100µA
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
EFFICIENCY vs. LOAD CURRENT
(1.2V/3A)
MAX1966 toc01
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5.0V
VIN = 3.3V
MAX1966
FIGURE 1
EFFICIENCY vs. LOAD CURRENT (1.8V/3A)
MAX1966
MAX1966 toc02
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5.0V
VIN = 3.3V
MAX1966
FIGURE 1
EFFICIENCY vs. LOAD CURRENT (1.2V/5A)
MAX1966
MAX1966 toc03
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5.0V
VIN = 5.0V
VIN = 3.3VVIN = 3.3V
MAX1966
FIGURE 1
EFFICIENCY vs. LOAD CURRENT (1.8V/5A)
MAX1966
MAX1966 toc04
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5.0V
VIN = 3.3V
MAX1966
FIGURE 1
EFFICIENCY vs. LOAD CURRENT (1.2V/3A)
MAX1967
MAX1966 toc05
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5V
VIN = 12V
MAX1967
FIGURE 2
EFFICIENCY vs. LOAD CURRENT (1.8V/3A)
MAX1967
MAX1966 toc06
LOAD CURRENT (A)
EFFICIENCY (%)70
VIN = 5V
VIN = 12V
MAX1967
FIGURE 2
EFFICIENCY vs. LOAD CURRENT (3.3V/3A)
MAX1967
MAX1966 toc07
LOAD CURRENT (A)
EFFICIENCY (%)70VIN = 5V
VIN = 12V
MAX1967
FIGURE 2
EFFICIENCY vs. LOAD CURRENT (1.2V/5A)
MAX1967
MAX1966 toc08
LOAD CURRENT (A)
EFFICIENCY (%)70VIN = 5V
VIN = 5V
VIN = 12V
VIN = 20V
MAX1967
FIGURE 2
EFFICIENCY vs. LOAD CURRENT (1.8V/5A)
MAX1967
MAX1966 toc09
LOAD CURRENT (A)
EFFICIENCY (%)70VIN = 5V
VIN = 12V
VIN = 20V
MAX1967
FIGURE 2
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
EFFICIENCY vs. LOAD CURRENT (3.3V/5A)
MAX1967
MAX1966 toc10
LOAD CURRENT (A)
EFFICIENCY (%)70VIN = 5V
VIN = 12V
VIN = 24V
MAX1967
FIGURE 298
FREQUENCY vs. INPUT VOLTAGE
MAX1966 toc11
INPUT VOLTAGE (V)
FREQUENCY (kHz)
MAX1966
VOUT = 1.8V
MAX1967
VOUT = 3.3V
FREQUENCY vs. TEMPERATURE
MAX1966 toc12
TEMPERATURE (°C)
FREQUENCY (kHz)
2A/div
2A/div
200mV/div
INDUCTOR
CURRENT
IOUT
VOUT
400ms/div
LOAD STEP RESPONSE
MAX1966 toc15
VIN = 5.0V, VOUT = 1.8V
L = 22μH
ILOAD = 0.1 TO 3A
1A/div
1V/div
2V/div
INDUCTOR
CURRENT
VOUT
VIN
2ms/div
START-UP WAVEFORM
MAX1966 toc16
NO LOAD
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
MAX1967 SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1966 toc14
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX1967
VOUT = 3.3V
MAX1966 SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX1966 toc13
INPUT VOLTAGE (V)
SUPPLY CURRENT (mA)
MAX1966
VOUT = 1.8V
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
MAX1966 toc17
IOUT
VIN = 5.0V
VIN = 1.8V
L = 22μFypical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
1A/div
1V/div
2V/div
INDUCTOR
CURRENT
VOUT
VIN
10ms/div
SHUTDOWN WAVEFORMS
MAX1966 toc18NO LOAD
Pin Description
PIN
MAX1966MAX1967
NAMEFUNCTION10BSTPositive Supply of DH Driver. Connect 0.1µF ceramic capacitor between BST and LX.1COMP/ENCompensation Pin. Pulling COMP/EN low with an open-collector or open-drain device
turns off the output.2FBFeedback Input. Connect a resistive divider network to set VOUT. FB threshold is 0.8V.3VCCInternal Chip Supply. Connect to VL via a 10Ω resistor.4VINPower Supply for LDO Regulator in the MAX1967 and Chip Supply for the MAX1966.
Bypass with a ceramic capacitor to ground (see application circuit).5VLOutput of Internal 5V LDO. Bypass with a 2.2µF capacitor to GND, or if VIN < 5.5,
connect VL to VIN and bypass with a 0.1µF capacitor to GND.6DLLow-Side External MOSFET Gate-Driver Output. DL swings from VL to GND.7GNDGround and Negative Current-Sense InputLXInductor Switching Node. LX is used for both current limit and the return supply of the
DH driver.9DHHigh-Side External MOSFET Gate-Driver Output. DH swings from BST to LX.
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
Detailed Description
The MAX1966/MAX1967 are BiCMOS switch-mode
power-supply controllers designed to implement sim-
ple, buck-topology regulators in cost-sensitive applica-
tions. The main power-switching circuit consists of two
N-channel MOSFETs (or a dual MOSFET), an inductor,
and input and output filter capacitors. An all N-channel
synchronous-rectified design provides high efficiency
at reduced cost. Gate drive for the N-channel high-side
switch is provided by a flying capacitor boost circuit
that uses a 0.1µF capacitor connected to BST.
Major circuit blocks of the MAX1966/MAX1967 are
shown in Figures 1 and 2: Control LogicGate Driver OutputsCurrent-Limit ComparatorClock GeneratorRamp GeneratorError AmplifierError ComparatorSoft-Start5V Linear Regulator (MAX1967)800mV ReferenceThermal Shutdown
In the MAX1996, most blocks are powered from VIN. In
the MAX1967, an internal 5V linear regulator steps
down the input voltage to supply both the IC and the
gate drivers. The synchronous-rectified gate driver is
directly powered from 5V VL, while the high-side-switch
gate driver is indirectly powered from VLplus an exter-
nal diode-capacitor boost circuit.
Resistorless Current Limit
The MAX1966/MAX1967 use the RDS(ON)of the low-
side N-channel MOSFET to sense the current. This
eliminates the need for an external sense resistor usual-
ly placed in series with the output. The voltage mea-
sured across the low-side RDS(ON)is compared to a
fixed -305mV reference (Figures 1 and 2).The peak
inductor current limit is given by the equation below:
MOSFET Gate Drivers
The DH and DL drivers are optimized for driving
MOSFETs with low gate charge. An adaptive dead-time
circuit monitors the DL output and prevents the high-
side FET from turning on until the low-side MOSFET is
fully off. There must be a low-resistance, low-inductance
connection from the DL driver to the MOSFET gate for
the adaptive dead-time circuit to work properly.
Otherwise, the sense circuitry in the MAX1966/
MAX1967 detects the MOSFET gate as off while there
is charge left on the gate. Use very short, wide traces
measuring no less than 50mils to 100mils wide if the
MOSFET is 1in away from the MAX1966/MAX1967. The
same type of adaptive dead-time circuit monitors the
DH off edge. The same recommendations apply for the
gate connection of the high-side MOSFET.
The internal pulldown transistor that drives DL low is
robust, with a 1.1Ωtypical on-resistance. This helps
prevent DL from being pulled up due to capacitive cou-
pling from the drain to the gate of the low-side synchro-
nous-rectifier MOSFET during the fast rise time of the
inductor node. The gate drivers are capable of driving
up to 1A. Use MOSFETs with combined total gate
charge of less than 200nC and a maximum VTHof 3.5V.
Internal Soft-Start
The MAX1966/MAX1967 feature an internally set soft-
start function that limits inrush current. It accomplishes
this by ramping the internal reference input to the con-
troller transconductance amplifier from 0 to the 0.8V
reference voltage. The ramp time is 1024 oscillator
cycles that begins when initial power is applied. At the
nominal 100kHz switching rate, the soft-start ramp is
approximately 10ms. The soft-start does not function if
the MAX1966/MAX1967 are shut down by pulling
COMP/EN low.
High-Side Gate-Drive Supply (BST)
Gate-drive voltage for the high-side N-channel switch is
generated by a flying-capacitor boost circuit (Figures 3
and 4). The flying capacitor is connected between BST
and LX.
On startup, the synchronous rectifier (low-side MOS-
FET) forces LX to ground and charges the boost
capacitor to 5V. On the second half-cycle, the
MAX1966/MAX1967 turn on the high-side MOSFET by
closing an internal switch between BST and DH. This
provides the necessary gate-to-source voltage to drive
the high-side FET gate above its source at the input
voltage.
Internal 5V Linear Regulator
(MAX1967)
All MAX1967 functions are internally powered from an
on-chip, low-dropout 5V regulator. The MAX1967 has a
maximum regulator input voltage (VVIN) of 28V. The
VCC pin must be connected to VL through a 10Ωresis-
tor and VL must be bypassed with a 2.2µF capacitor to
GND. For operation at VVIN< 5V, connect VL to VIN
ImVRPEAKDSON=305/()
MAX1966/MAX1967
Low-Cost Voltage-Mode PWM
Step-Down Controllers
MAX1966
VOUT
2.7V TO
5.5V INPUT
VIN
COMP/EN
GND
BSTC4C1
Figure 3. MAX1966 Typical Application
MAX1967
5V TO
28V INPUT
VIN
COMP/EN
GND
BST
VCC
VOUTC4R4
10Ω
10Ω
Figure 4. MAX1967 Typical Application
TEMPERATURE
SHUTDOWN
CONTROL
LOGIC
RAMP
GENERATOR
SOFT-START
100kHZ
CLOCK
GENERATOR
GND
CURRENT-LIMIT
COMPARATOR
ERROR
COMPARATOR
ERROR
AMPLIFIER
-305mV
BSTVIN
COMP/EN
800mV
REF
MAX1966
Figure 1. MAX1966 Functional Diagram
TEMPERATURE
SHUTDOWN
CONTROL
LOGIC
5V LINEAR
REGULATOR
RAMP
GENERATOR
SOFT-START
100kHZ
CLOCK
GENERATOR
GND
CURRENT-LIMIT
COMPARATOR
ERROR
COMPARATOR
ERROR
AMPLIFIER
-305mV
BST
VIN
COMP/EN
VCC
800mV
REF
INTERNAL
CHIP
SUPPLY
MAX1967
Figure 2. MAX1967 Functional Diagram
SEE TABLE 1 FOR COMPONENT VALUES.SEE TABLE 1 FOR COMPONENT VALUES.

Partno	Mfg	Dc	Qty	Available	Descript
MAX1967EUB+ \|MAX1967EUB	MAXIM	N/a	1080	avai	Low-Cost Voltage-Mode PWM Step-Down Controllers
MAX1967EUB+ \|MAX1967EUB	MAX	N/a	32	avai	Low-Cost Voltage-Mode PWM Step-Down Controllers
MAX1967EUB+T \|MAX1967EUBT	MAXIM	N/a	5000	avai	Low-Cost Voltage-Mode PWM Step-Down Controllers