19-2532; Rev 2; 6/03
KIT
ATION
EVALU
E
BL
AVAILA
300mA LDO Linear Regulators with
Internal Microprocessor Reset Circuit
General Description
Features
o
3
✕
3 UCSP, 6-Pin SOT23, and 8-Pin QFN Packages
o
Preset +1.5V to +3.3V Output (100mV Increments)
o
SET Pin for Adjustable Output Voltage
o
75µV
RMS
LDO Output Voltage Noise
(MAX6477–MAX6484)
o
±2.0% Accuracy Over Temperature
o
Guaranteed 300mA Output Current
o
Low Dropout Voltage
55mV at 150mA
114mV at 300mA
o
82µA Supply Current, 0.1µA Shutdown Current
o
Input Reverse Current, Thermal and Short-Circuit
Protection
o
Microprocessor Reset with Four Timeout Options
o
Push-Pull or Open-Drain
RESET
o
Manual Reset Input
o
Remote Feedback Sense
MAX6469–MAX6484
The MAX6469–MAX6484 are low-dropout linear regula-
tors with a fully integrated microprocessor reset circuit.
Each is available with preset output voltages from +1.5V
to +3.3V in 100mV increments and delivers up to 300mA
of load current. These devices consume only 82µA of
supply current. The low supply current, low dropout volt-
age, and integrated reset functionality make these
devices ideal for battery-powered portable equipment.
The MAX6469–MAX6484 include a reset output that indi-
cates when the regulator output drops below standard
microprocessor supply tolerances (-7.5% or -12.5% of
nominal output voltage). This eliminates the need for an
external microprocessor supervisor, while ensuring that
supply voltages and clock oscillators have stabilized
before processor activity is enabled. Push-pull and open-
drain active-low reset outputs are available, with reset
timeout periods of 2.5ms, 20ms, 150ms, or 1200ms (min).
The MAX6469/MAX6470/MAX6473–MAX6478/MAX6481–
MAX6484 also have a shutdown feature that reduces the
supply current to 0.1µA (typ). The MAX6471–MAX6474/
MAX6479–MAX6482 offer a manual reset input to assert a
microprocessor reset while the regulator output is within
specification. The MAX6475/MAX6476/MAX6483/
MAX6484 feature a remote feedback sense pin for use
with an external NPN transistor for higher-current applica-
tions. The MAX6469–MAX6476 are available in 6-pin
SOT23 and 8-pin thin QFN packages. The MAX6477–
MAX6484 are available in a 3
×
3 chip-scale package
(UCSP™). All devices are specified for operation from
-40°C to +85°C.
Ordering Information
PART
MAX6469UT_
_ _D_-T
MAX6469TA_ _ _D_*
MAX6470UT_
_ _D_-T
MAX6470TA_ _ _D_*
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-
PACKAGE
6 SOT23-6
8 Thin QFN
6 SOT23-6
8 Thin QFN
Applications
Hand-Held Instruments (PDAs, Palmtops)
PCMCIA Cards/USB Devices
Cellular/Cordless Telephones
CD/DVD Drives
Notebook Computers
Digital Cameras
Bluetooth Modules/Wireless LAN
*Future
product—contact factory for availability.
Note:
The first “_ _”are placeholders for the output voltage levels
of the devices. Desired output voltages are set by the suffix found
in the Output Voltage Suffix Guide (Table 1). The third “_” is a
placeholder for the reset threshold accuracy. Desired reset
threshold accuracy is set by the suffix found in the Reset
Threshold Accuracy Guide (Table 2). The “_” following the D is a
placeholder for the reset timeout delay time. Desired reset timeout
delay time is set by the suffix found in the Reset Timeout Delay
Guide (Table 3). For example, the MAX6481BL30BD4-T has a
3.0V output voltage, 12.5% reset threshold tolerance, and a
1200ms (min) reset timeout delay. Sample stock is generally avail-
able on standard versions only (Table 4). Standard versions
require a minimum order increment of 2.5k units. Nonstandard
versions must be ordered in 10k-unit increments. Contact factory
for availability.
Ordering Information continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
Pin Configurations appear at end of data sheet.
Typical Operating Circuits appear at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
300mA LDO Linear Regulators with Internal
Microprocessor Reset Circuit
MAX6469–MAX6484
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND, unless otherwise noted.)
IN,
SHDN,
OUT, FB ..................................................-0.3V to +7V
MR,
SET .......................................................-0.3V to (V
IN
+ 0.3V)
RESET
(push-pull) ...................................-0.3V to (V
OUT
+ 0.3V)
RESET
(open drain)..................................................-0.3V to +7V
OUT Short Circuit .......................................................Continuous
Input/Output Current (all pins except IN and OUT) ............20mA
Continuous Power Dissipation (T
A
= +70°C)
3 x 3 UCSP (derate 10.5mW/°C above +70°C) ............840mW
6-Pin SOT23 (derate 9.1mW/°C above +70°C).............727mW
8-Pin Thin QFN
(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
Note 1:
The MAX6477–MAX6484 are constructed using a unique set of packaging techniques that impose a limit on the thermal pro-
file the devices can be exposed to during board-level solder attach and rework. This limit permits only the use of the solder
profiles recommended in the industry-standard specification, JEDEC 020A, paragraph 7.6, Table 3 for IR/VPR and
Convection reflow. Pre-heating is required. Hand or wave soldering is not allowed.
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
(V
IN
= (V
OUT
+ 0.5V) or +2.5V, whichever is greater, C
OUT
= 3.3µF, T
A
= -40°C to +85°C. Typical specifications are at T
A
= +25°C,
unless otherwise noted.) (Note 2)
PARAMETER
Input Voltage Range
Input Undervoltage Lockout
Supply Current (Ground Current)
Shutdown Supply Current
REGULATOR CIRCUIT
Output Current
Output Voltage Accuracy (Fixed
Output Voltage Operation,
Table 1) MAX6469–MAX6476
Output Voltage Accuracy (Fixed
Output Voltage Operation,
Table 1) MAX6477–MAX6484
Adjustable Output Voltage Range
SET Reference Voltage
SET Dual Mode
TM
Threshold
SET Input Leakage Current
1mA
≤
I
OUT
≤
150mA, T
A
= +25°C
1mA
≤
I
OUT
≤
150mA, T
A
= -40°C to +85°C
1mA
≤
I
OUT
≤
300mA, T
A
= -40°C to +85°C
2mA
≤
I
OUT
≤
100mA, T
A
= +25°C
2mA
≤
I
OUT
≤
100mA, T
A
= -40°C to +85°C
2mA
≤
I
OUT
≤
300mA, T
A
= -40°C to +85°C
(Note 3)
V
SET
I
SET
V
SET
= 0, +1.2V (Note 3)
SYMBOL
V
IN
V
UVLO
I
Q
I
SHDN
V
IN
falling
I
OUT
= 0
I
OUT
= 300mA
T
A
= +25°C
300
-1.3
-2.3
-2.7
-1.1
-2.0
-2.5
V
SET
1.200
CONDITIONS
MIN
2.5
2.25
82
96
0.1
TYP
MAX
5.5
2.47
136
1
UNITS
V
V
µA
µA
mA
+1.3
+2.3
+2.7
+1.1
+2.0
+2.5
5.0
1.258
±100
V
V
mV
nA
%
%
1.229
185
±20
Dual Mode is a trademark of Maxim Integrated Products, Inc.
2
_______________________________________________________________________________________
300mA LDO Linear Regulators with Internal
Microprocessor Reset Circuit
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= (V
OUT
+ 0.5V) or +2.5V, whichever is greater, C
OUT
= 3.3µF, T
A
= -40°C to +85°C. Typical specifications are at T
A
= +25°C,
unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
V
OUT
= +3.3V
(fixed output operation)
V
OUT
= +3.0V
(fixed output operation)
∆V
DO
V
OUT
= +2.8V
(fixed output operation)
V
OUT
= +2.5V
(fixed output operation)
Output Current Limit
Input Reverse Leakage Current
(OUT to IN Leakage Current)
Startup Time Response
SHDN
Input Low Voltage
SHDN
Input High Voltage
SHDN
Input Current
Thermal-Shutdown Temperature
Thermal-Shutdown Hysteresis
Line Regulation
Load Regulation
T
SHDN
∆T
SHDN
V
OUT
= 1.5V, 2.5V
≤
V
IN
≤
5.5V,
I
OUT
= 10mA
V
OUT
= 1.5V, V
IN
= 2.5V, 1mA
≤
I
OUT
≤
150mA
10Hz to 100kHz,
C
IN
= 0.1µF,
I
OUT
= 100mA,
V
OUT
= 1.5V
MAX64_ _ _ _ _ _ A
V
THOUT
MAX64_ _ _ _ _ _ B
MAX6469–MAX6476
MAX6477–MAX6484
V
IL
V
IH
SHDN
= V
IN
or GND
0.7
×
V
IN
-1
0.1
180
20
0.09
0.2
150
µV
RMS
75
+1
V
IN
≥
2.5V (Note 3)
V
IN
= 4V, V
OUT
= 5.5V,
SHDN
deasserted
Rising edge of V
IN
or
SHDN
to V
OUT
within specification, R
L
= 68Ω, SET = GND,
I
OUT
= 10mA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 300mA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 300mA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 300mA
I
OUT
= 50mA
I
OUT
= 150mA
I
OUT
= 300mA
450
0.01
1.5
MIN
TYP
23
55
114
25
61
114
26
65
137
30
75
158
MAX
32
90
180
40
100
190
50
110
210
60
150
250
UNITS
MAX6469–MAX6484
Dropout Voltage
(Notes 3, 4)
mV
mA
µA
20
0.3
×
V
IN
µs
V
V
µA
°C
°C
%/V
%
Output Voltage Noise
RESET CIRCUIT
V
OUT
Reset Threshold
(V
FB
for MAX6475/MAX6476/
MAX6483/MAX6484) (Note 5)
V
OUT
to Reset Delay
(V
FB
for MAX6475/MAX6476/
MAX6483/MAX6484)
D1
Reset Timeout Period
(Note 6)
t
RP
D2
D3
D4
2.5
20
150
1200
90
85
92.5
87.5
35
3.75
30
225
1800
5.0
40
300
2400
ms
95
90
%V
OUT
µs
_______________________________________________________________________________________
3
300mA LDO Linear Regulators with Internal
Microprocessor Reset Circuit
MAX6469–MAX6484
ELECTRICAL CHARACTERISTICS (continued)
(V
IN
= (V
OUT
+ 0.5V) or +2.5V, whichever is greater, C
OUT
= 3.3µF, T
A
= -40°C to +85°C. Typical specifications are at T
A
= +25°C,
unless otherwise noted.) (Note 2)
PARAMETER
MR
Input Low Voltage
MR
Input High Voltage
MR
Minimum Input Pulse
MR
Glitch Rejection
MR
to Reset Delay
MR
Pullup Resistance
RESET
Output Voltage
(Open Drain)
Open-Drain Reset Output
Leakage Current
V
OL
I
LKG
V
OL
RESET
Output Voltage Push-Pull
V
OH
MR
to OUT
V
OUT
≥
1.0V, I
SINK
= 50µA,
RESET
asserted
V
OUT
≥
1.5V, I
SINK
= 3.2mA,
RESET
asserted
(Note 3)
V
OUT
≥
1.0V, I
SINK
= 50µA,
RESET
asserted
V
OUT
≥
1.5V, I
SINK
= 3.2mA,
RESET
asserted
V
OUT
≥
2.0V, I
SOURCE
= 500µA,
RESET
deasserted
0.8
×
V
OUT
25
SYMBOL
V
IL
V
IH
(Note 3)
0.7
×
V
OUT
1
120
200
40
70
0.3
0.4
1
0.3
0.4
V
CONDITIONS
MIN
TYP
MAX
0.3
×
V
OUT
UNITS
V
V
µs
ns
ns
kΩ
V
µA
Note 2:
Note 3:
Note 4:
Note 5:
Note 6:
All devices are 100% production tested at +25°C and are guaranteed by correlation for T
A
= T
MIN
to T
MAX
.
Guaranteed by design.
Dropout voltage is defined as (V
IN
- V
OUT
) when V
OUT
is 2% below the value of V
OUT
for V
IN
= V
OUT(NOM)
+ 1V.
MAX6473/MAX6474/MAX6481/MAX6482 are guaranteed by design for V
OUT
< 2.5V.
Select the reset timeout period using the
Reset Timeout Delay Guide
(Table 3). Insert the appropriate suffix in the part number
when ordering.
Typical Operating Characteristics
(V
IN
= 5V, V
OUT
= 3.3V, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted.)
GROUND CURRENT vs. INPUT VOLTAGE
(NO LOAD)
MAX6469 toc01
GROUND CURRENT vs. INPUT VOLTAGE
(300mA LOAD)
MAX6469 toc02
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAX6469 toc03
120
100
GROUND CURRENT (µA)
80
60
40
20
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
+85°C
+25°C
-40°C
120
100
GROUND CURRENT (µA)
+85°C
80
60
40
20
0
0
1
2
3
4
5
6
INPUT VOLTAGE (V)
+25°C
-40°C
150
125
PULSE DURATION (µs)
100
75
50
25
0
1
10
RESET THRESHOLD OVERDRIVE (mV)
RESET ASSERTS ABOVE
THIS LINE
100
4
_______________________________________________________________________________________
300mA LDO Linear Regulators with Internal
Microprocessor Reset Circuit
Typical Operating Characteristics (continued)
(V
IN
= 5V, V
OUT
= 3.3V, C
OUT
= 3.3µF, T
A
= +25°C, unless otherwise noted.)
REGION OF STABLE C
OUT
ESR
vs. LOAD CURRENT
MAX6469 toc05
MAX6469 toc06
MAX6469–MAX6484
DROPOUT VOLTAGE vs. LOAD CURRENT
MAX6469 toc04
PSRR vs. FREQUENCY
0
-10
-20
PSRR (dB)
V
OUT
= 3.3V
C
OUT
= 3.3µF
I
LOAD
= 30mA
5
125
V
OUT
= 3.3V
C
OUT
= 3.3µF
100
DROPOUT VOLTAGE (mV)
4
C
OUT
ESR (Ω)
75
3
C
OUT
= 4.7µF
2
C
OUT
= 3.3µF
-30
-40
50
25
-50
-60
0
50
100
150
200
250
300
0.01
0.1
1
10
100
1000
LOAD CURRENT (mA)
FREQUENCY (kHz)
1
STABLE REGION
0
0
0
50
100
150
200
250
300
LOAD CURRENT (mA)
OUTPUT NOISE
MAX6469 toc07
OUTPUT NOISE vs. FREQUENCY
V
IN
= 2.5V
V
OUT
= 1.5V
I
OUT
= 100mA
MAX6469 toc08
SHUTDOWN RESPONSE
MAX6469 toc09
V
IN
= 4.5V
V
OUT
= 3.3V
I
LOAD
= 100mA
100
80
100µV/div
V
RMS
(µV)
60
V
SHDN
5V/div
40
V
OUT
2V/div
I
LOAD
= 50mA
20
0
500µs/div
10
100
1k
FREQUENCY (Hz)
10k
100k
20ms/div
STARTUP RESPONSE
MAX6469 toc10
LOAD-TRANSIENT RESPONSE
MAX6469 toc11
LOAD-TRANSIENT RESPONSE
NEAR DROPOUT
MAX6469 toc12
V
IN
2V/div
V
IN
= 5V
V
OUT
= 3.3V
I
LOAD
= 100mA
V
OUT
2V/div
V
OUT
20mV/div
V
OUT
5mV/div
10µs/div
100µs/div
10µs/div
_______________________________________________________________________________________
5
单片机
