Datasheet MAX1951 (Analog Devices) - 2

1MHz, All-Ceramic, 2.6V to 5.5V Input, 2A PWM Step-Down DC-to-DC Regulators ABSOLUTE MAXIMUM RATINGS
IN, VCC to GND ..-0.3V to +6V Package Junction-to-Case COMP, FB, REF to GND ...-0.3V to (VCC + 0.3V) Thermal Resistance (θJC) (Note 2) ..32°C/W LX to Current (Note 1)...±4.5A Operating Temperature Range PGND to GND ...Internally Connected MAX195_ ESA..-40°C to +85°C Continuous Power Dissipation (TA = +85°C) Junction Temperature Range ..-40°C to +150°C 8-Pin SO (derate 12.2mW/°C above +70°C)..976mW Storage Temperature Range ...-65°C to +150°C Package Junction-to-Ambient Lead Temperature (soldering, 10s) ...+300°C Thermal Resistance (θJA) (Note 2)...82°C/W
Note 1:
LX has internal clamp diodes to PGND and IN. Applications that forward bias these diodes should take care not to exceed the IC’s package power dissipation limits.
Note 2:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer board. For detailed information on package thermal considerations, refer to
www.maxim-ic.com/thermal-tutorial
. 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.
MAX1951/MAX1952 ELECTRICAL CHARACTERISTICS
(VIN = VCC = 3.3V, PGND = GND, FB in regulation, CREF = 0.1µF,
TA = 0°C to +85°C
, unless otherwise noted. Typical values are at TA = +25°C.)
PARAMETER CONDITIONS MIN TYP MAX UNITS IN AND VCC
IN Voltage Range 2.6 5.5 V Supply Current S w i tchi ng w i th no l oad , LX unconnected VIN = 5.5V 6 10 mA Shutdown Current COMP = GND 0.5 1.0 mA V V CC Undervoltage Lockout CC rising 2.35 2.5 When LX starts/stops switching V Threshold VCC falling 2 2.25
REF
REF Voltage IREF = 0µA, VIN = 2.6V to 5.5V 1.96 2 2.03 V REF Load Regulation IREF = 0 to 40µA, VIN = 2.6V to 5.5V 0.01 0.2 % REF Line Regulation IREF = 20µA, VIN = 2.6V to 5.5V 0.01 0.4 % REF Shutdown Resistance From REF to GND, COMP = GND 12 22 Ω
COMP
MAX1951 40 60 80 COMP Transconductance From FB to COMP, VCOMP = 1.25V µS MAX1952 26.7 40 53.3 COMP Clamp Voltage, Low VIN = 2.6V to 5.5V, VFB = 1.3V 0.6 1 1.2 V COMP Clamp Voltage, High VIN = 2.6V to 5.5V, VFB = 1.1V 1.97 2.15 2.28 V COMP Shutdown Resistance From COMP to GND, VIN = 2V 15 30 Ω COMP rising 0.6 1 COMP Shutdown Threshold When LX starts/stops switching V COMP falling 0.17 0.4 COMP Startup Current COMP = GND 15 25 40 µA
FB
Output Voltage Range When using external feedback resistors to drive FB 0.8 VIN V (MAX1951) FB Regulation Voltage V V C OM P = 1V to 2V , IN = 2.6V to 5.5V MAX1951 0.787 0.795 0.803 V (Error Amp Only) IOU T = 0 to 1.5A VIN = 2.8V to 5.5V MAX1952 1.773 1.8 1.827 FB Input Resistance MAX1952 13 18 28 kΩ FB Input Bias Current MAX1951 -0.1 +0.1 µA
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