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MAX1857EUA47+T

P1-P3P4-P6P7-P9P10-P10
General Description
The MAX1857 low-dropout linear regulator operates
from a +2.5V to +5.5V supply and delivers a guaran-
teed 500mA load current with low 120mV dropout. The
high-accuracy (±1%) output voltage is preset at an
internally trimmed 4.75V or can be adjusted from 1.25V
to 5.0V with an external resistive divider.
An internal PMOS pass transistor allows the low 135µA
supply current to remain independent of load, making
this device ideal for portable battery-operated equip-
ment such as personal digital assistants (PDAs), cellu-
lar phones, cordless phones, base stations, and
notebook computers.
Other features include an active-low open-drain reset
output with a 4.5ms timeout period that indicates when
the output is out of regulation, a 0.1µA shutdown mode,
short-circuit protection, and thermal shutdown protec-
tion. The device is available in a miniature 8-pin µMAX
package. For higher power applications, refer to the
MAX1792 and MAX1793 data sheets.
________________________Applications
Notebook Computers
Cellular and Cordless Telephones
PDAs
Palmtop Computers
Base Stations
USB Hubs
Docking Stations
Features
♦ Guaranteed 500mA Output Current
♦ Low 120mV Dropout at 500mA
♦ Up to ±1% Output Voltage Accuracy
Preset at 4.75V
Adjustable from 1.25V to 5.0V
♦ Reset Output with 4.5ms Timeout Period
♦ Low 135µA Ground Current
♦ 0.1µA Shutdown Current
♦ Thermal Overload Protection
♦ Output Current Limit
♦ Tiny µMAX Package
MAX1857
500mA, Low-Dropout,
Ripple-Rejecting LDO in µMAX
________________________________________________________________ Maxim Integrated Products 1
SET
GNDSHDN
1
2
8
7
OUT
OUTIN
RST
IN
µMAX
TOP VIEW
3
4
6
5
MAX1857
Pin Configuration
NC
MAX1857
IN
IN
ON
OFF
C
IN
1µF
SHDN
OUT
OUT
RST
GNDSET
C
OUT
3.3µF
TO
µC
V
IN
= +5V V
OUT
= 4.75V
R
RST
100k
Typical Operating Circuit
19-1812; Rev 0; 1/01
Ordering Information
PART*
TEMP. RANGE
PIN-PACKAGE
MAX1857EUA47
-40°C to +85°C
8 µMAX
*Contact factory for other preset output voltages.
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX1857
500mA, Low-Dropout,
Ripple-Rejecting LDO in µMAX
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= +5.25V, V
OUT
= 4.75V, SHDN = IN, SET = GND, T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +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.
IN, SHDN, RST, SET to GND ....................................-0.3V to +6V
OUT to GND ................................................-0.3V to (V
IN
+ 0.3V)
Output Short-Circuit Duration ........................................Indefinite
Continuous Power Dissipation (T
A
= +70°C)
8-Pin µMAX (derate 4.5mW/°C above +70°C) .............362mW
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
PARAMETER
SYMBOL
CONDITIONS
MIN
MAX
UNITS
Input Voltage V
IN
2.5 5.5 V
Input Undervoltage Lockout
V
UVLO
Rising, 75mV hysteresis 2.0
2.15
2.3 V
V
OUT
≥ 2.5V -1 +1
I
OUT
= 100mA,
T
A
= +85°C
V
OUT
< 2.5V
-1.5 +1.5
%
I
OUT
= 100mA, T
A
= 0°C to +85°C-2 +2
Output Voltage Accuracy
(Preset Mode)
V
OUT
I
OUT
= 1mA to 500mA, V
IN
> V
OUT + 0.5V,
T
A = 0°C to +85°C
-3 +3
%
Adjustable Output Voltage
Range
V
SET
= 1.25V
1.25
5V
T
A
= +85°C
1.229 1.250 1.271
SET Voltage Threshold
(Adjustable Mode)
V
SET
V
IN
= +2.7V,
V
OUT
set to 2.0V,
I
OUT
= 100mA
T
A
= 0°C to +85°C
1.219 1.281
V
Maximum Output Current I
OUT
V
IN
≥ 2.7V 500
mA
RMS
Short-Circuit Current Limit I
LIM
V
OUT
= 0, V
IN
≥ 2.7V
0.55
1.2 2.2 A
In-Regulation Current Limit V
OUT
> 96% of nominal value, V
IN
≥ 2.7V 2.0 A
SET Dual Mode™ Threshold 50 100 150 mV
SET Input Bias Current I
SET
V
SET
= 1.25V
-100 +100
nA
I
OUT
= 1mA 135 250
Ground-Pin Current I
Q
I
OUT
= 500mA 175
µA
Dropout Voltage (Note 1)
V
IN
-
V
OUT
I
OUT
= 500mA 120 175 mV
Line Regulation
∆V
LNR
V
IN
from (V
OUT
+ 100mV) to 5.5V,
I
LOAD
= 5mA
-0.15
0
+0.15
%/V
Load Regulation
∆V
LDR
I
OUT
= 1mA to 500mA 0.4 1.0 %
Output Voltage Noise 10Hz to 1MHz, C
OUT = 3.3µF (ESR < 0.1Ω)
115
µV
RMS
SHUTDOWN
Shutdown Supply Current I
OFF
SHDN = GND, V
IN
= 5.5V 0.1 15 µA
V
IH
2.5V < V
IN
< 5.5V 1.6
SHDN Input Threshold
V
IL
2.5V < V
IN
< 5.5V 0.6
V
SHDN Input Bias Current SHDN = IN or GND 10 100 nA
Dual Mode is a trademark of Maxim Integrated Products.
MAX1857
500mA, Low-Dropout,
Ripple-Rejecting LDO in µMAX
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS
(V
IN
= +5.25V, V
OUT
= 4.75V, SHDN = IN, SET = GND, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
ELECTRICAL CHARACTERISTICS (continued)
((V
IN
= +5.25V, V
OUT
= 4.75V, SHDN = IN, SET = GND, T
A
= 0°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.)
PARAMETER
SYMBOL
CONDITIONS
MIN
MAX
UNITS
RESET OUTPUT
Reset Output Low Voltage V
OL
RST sinking 1mA
0.01
0.1 V
Operating Voltage Range for
Valid Reset
RST sinking 100µA 1.0 5.5 V
RST Output High Leakage
Current
V
RST
= +5.5V 100 nA
RST Threshold Rising edge, referred to V
OUT(NOMINAL)
83 86 89 %
RST Release Delay t
RP
Rising edge of OUT to rising edge of RST 1.4 4.5 8 ms
THERMAL PROTECTION
Ther m al S hutd ow n Tem p er atur e
T
SHDN
170 °C
Thermal Shutdown Hysteresis
∆T
SHDN
20 °C
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS
Input Voltage V
IN
2.5 5.5 V
Input Undervoltage Lockout V
UVLO
Rising or falling 2.0 2.3 V
Output Voltage Accuracy
(Preset Mode)
V
OUT
I
OUT
= 1mA to 500mA -3 +3 %
Adjustable Output Voltage
Range
V
SET
= 1.25V 1.25 5 V
SET Voltage Threshold
(Adjustable Mode)
V
SET
I
OUT
= 100mA 1.212 1.288 V
Maximum Output Current I
OUT
500 mA
RMS
Short-Circuit Current Limit I
LIM
V
OUT
= 0 0.55 2.2 A
SET Dual Mode Threshold 50 150 mV
SET Input Bias Current I
SET
V
SET
= 1.25V -100 +100 nA
Ground-Pin Current I
Q
I
OUT
= 1mA 250 µA
Dropout Voltage (Note 1)
V
IN
-
V
OUT
I
OUT
= 500mA 175 mV
Line Regulation ∆V
LNR
V
IN
from (V
OUT
+ 100mV) to 5.5V,
I
LOAD
= 5mA
-0.15 +0.15 %/V
Load Regulation ∆V
LDR
I
OUT
= 1mA to 500mA 1.0 %
SHUTDOWN
Shutdown Supply Current I
OFF
SHDN = GND, V
IN
= +5.5V
15 µA
V
IH
2.5V < V
IN
< 5.5V 1.6
SHDN Input
Threshold
V
IL
2.5V < V
IN
< 5.5V 0.6
V
SHDN Input Bias Current SHDN = IN or GND 100 nA
P1-P3P4-P6P7-P9P10-P10

MAX1857EUA47+T

Mfr. #:
Buy MAX1857EUA47+T
Manufacturer:
Maxim Integrated
Description:
LDO Voltage Regulators 500mA Ripple-Rejecting
Lifecycle:
New from this manufacturer.
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