Datasheet

IN, SHDN to GND...................................................-0.3V to +25V
LX to GND.......................................................-2V to (V
IN
+ 0.3V)
OUT, FB to GND.......................................................-0.3V to +6V
Continuous Power Dissipation (T
A
= +70°C) (Note 1)
6-Pin SOT23 (derate 8.7mW/°C above +70°C)...........696mW
6-Pin TDFN (derate 24.4mW/°C above +70°C).........1951mW
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
(Circuits of Figures 1 (MAX1836) and 2 (MAX1837), V
IN
= 12V, SHDN = IN, T
A
= 0°C to +85°C. Typical values are at T
A
= +25°C,
unless otherwise noted.)
Dual Mode is a trademark of Maxim Integrated Products, Inc.
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
Input Supply Range V
IN
4.5 24 V
Input Undervoltage Lockout
Threshold
V
UVLO
V
IN
rising 3.55 4.0 4.4
V
V
IN
falling 3.45 3.9 4.3
Input Supply Current I
IN
12 25 µA
Input Supply Current in Dropout I
IN(DROP)
V
IN
= 5V 18 µA
Input Shutdown Current SHDN = GND 3 7 µA
Output Voltage (Preset Mode) V
OUT
FB = GND,
I
LOAD
= 0 to 125mA
(MAX1836) or
250mA (MAX1837)
MAX183_EUT50,
MAX183_ETT50
4.80 5.00 5.20
V
MAX183_EUT33,
MAX183_ETT33
3.168 3.30 3.432
Output Voltage Range
(Adjustable Mode)
V
OUT
(Note 2) 1.25 V
IN
V
Feedback Set Voltage
(Adjustable Mode)
V
FB
1.200 1.25 1.300 V
OUT Bias Current V
OUT
= 5V 2.5 7.4 µA
FB Bias Current I
FB
V
FB
= 0 or 1.25V, T
A
= +25°C -25 +25 nA
FB Dual Mode
TM
Threshold V
FB
rising or falling 50 100 150 mV
LX Switch Minimum Off-Time t
OFF(MIN)
0.2 0.4 0.6 µs
LX Switch Maximum On-Time t
ON(MAX)
V
FB
= 1.3V 7 10 13 µs
LX Switch On-Resistance R
LX
V
IN
= 6V 1.1 2 Ω
LX Current Limit I
LIM
MAX1836 250 312 450
mA
MAX1837 500 625 850
LX Zero-Crossing Threshold -75 +75 mV
MAX1836/MAX1837 24V Internal Switch, 100% Duty Cycle,
Step-Down Converters
www.maximintegrated.com
Maxim Integrated │ 2
Note 1: Thermal properties are specified with product mounted on PC board with 1in
2
of copper area and still air.
Absolute Maximum Ratings
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.
Electrical Characteristics