tent.
MAX667 +5V/Programmable Low-Dropout Voltage Regulator
_______________General Description
The MAX667 low-dropout, positive, linear voltage regu-
lator supplies up to 250mA of output current. With no
load, it has a typical quiescent current of 20µA. At
200mA of output current, the input/output voltage differ-
ential is typically 150mV. Other features include a low-
voltage detector to indicate power failure, as well as
early-warning and low-dropout detectors to indicate an
imminent loss of output voltage regulation. A shutdown
control disables the output and puts the circuit into a
low quiescent-current mode.
The MAX667 employs Dual Mode operation. One
mode uses internally trimmed feedback resistors to pro-
duce +5V. In the other mode, the output may be varied
from +1.3V to +16V by connecting two external resistors.
The MAX667 is a pin-compatible upgrade to the
MAX666 in most applications where the input voltages
are above +3.5V. Choose the MAX667 when high out-
put currents and/or low dropout voltages are desired,
as well as for improved performance at higher
temperatures.
________________________Applications
Battery-Powered Devices
Pagers and Radio Control Receivers
Portable Instruments
Solar-Powered Instruments
____________________________Features
o
350mV Max Dropout at 200mA
o
250mA Output Current
o
Normal Mode: 20µA Typ Quiescent Current
Shutdown Mode: 0.2µA Typ Quiescent Current
o
Low-Battery Detector
o
Fixed +5V (Min Component Count) or
Adjustable Output
o
+3.5V to +16.5V Input
o
Dropout Detector Output
o
10µF Output Capacitor
______________Ordering Information
MAX667
+5V/Programmable Low-Dropout
Voltage Regulator
________________________________________________________________
Maxim Integrated Products
1
__________________Pin Configuration
__________Typical Operating Circuit
Call toll free 1-800-998-8800 for free samples or literature.
19-3894; Rev 3; 10/94
MAX667
1
2
3
4
8
7
6
5
IN
LBO
SET
SHDN
GND
LBI
OUT
DD
MAX667
DIP/SO
TOP VIEW
MAX667
GND
SHDN
SET
OUT
+5V OUT
IN
C1
10
µ
F
+6.3V
BATTERY
PART
TEMP. RANGE
PIN-PACKAGE
MAX667CPA
0°C to +70°C
8 Plastic DIP
MAX667CSA
0°C to +70°C
8 SO
MAX667C/D
0°C to +70°C
Dice
*
MAX667EPA
-40°C to +85°C
8 Plastic DIP
MAX667ESA
-40°C to +85°C
8 SO
MAX667MJA
-55°C to +125°C
8 CERDIP
* Contact factory for dice specifications.
TM
Dual Mode is a trademark of Maxim Integrated Products. MAX667
+5V/Programmable Low-Dropout
Voltage Regulator
2
_______________________________________________________________________________________
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.
Input Supply Voltage ...........................................................+18V
Output Short Circuited to Ground.........................................1sec
LBO Output Sink Current ....................................................50mA
LBO Output Voltage ...............................................GND to V
OUT
SHDN Input Voltage ....................................-0.3V to (V
IN
+ 0.3V)
Input Voltages LBI, SET................................-0.3V to (V
IN
- 1.0V)
Continuous Power Dissipation
Plastic DIP (derate 9.09mW/°C above +70°C) ............727mW
SO (derate 5.88mW/°C above +70°C) .........................471mW
CERDIP (derate 8.00mW/°C above +70°C) .................640mW
Operating Temperature Ranges
MAX667C_A........................................................0°C to +70°C
MAX667E_A .....................................................-40°C to +85°C
MAX667MJA ..................................................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
Note 1:
Dropout Voltage is V
IN
-V
OUT
when V
OUT
falls to 0.1V below its value at V
IN
= V
OUT
+ 2V.
Note 2:
Short-Circuit Current is pulse tested to maintain junction temperature. Short-circuit duration is limited by package dissipation.
PARAMETER
Line Regulation
SYMBOL
T
A
= +25°C
MIN
TYP
MAX
5
10
T
A
= T
MIN
to T
MAX
MIN
TYP
MAX
15
20
30
SET Reference Voltage
V
SET
50
1.225
20
25
35
0.2
1
1.20
1.25
2
Maximum Output Current
I
OUT
250
250
Output Leakage Current
Quiescent Current
I
Q
5
15
20
5
60
75
I
OUT
0.1
1
Short-Circuit Current
Dropout Voltage (Note1)
I
OUT
150
250
400
350
Load Regulation
450
50
100
250
Low-Battery Detector
Reference Voltage
V
LBI
1.225
1.195
1.255
Low-Battery Detector
Output Voltage
I
OUT
= 0µA
V
LBO
0.25
0.4
V
SHDN
Input Voltage
1.5
V
IN
1.5
SHDN Leakage Current
3.5
16.5
I
SHDN
0.01
±10
±1000
I
OUT
= 100µA
5
4.8
5.2
0.25
Dropout Detector Output
Voltage
Output Voltage
V
DD
3.5
V
OUT
5
4.75
5.25
CONDITIONS
V
IN
= 6V to 10V, I
OUT
= 10mA
V
SHDN
= 2V
V
IN
= 6V, 4.5V < V
OUT
< 5.5V
I
OUT
= 200mA
I
OUT
= 100µA
V
SHDN
= 2V
(Note 2)
I
OUT
= 200mA
I
OUT
= 10mA to 200mA
V
IN
= 9V, V
LBI
= 2V, I
LBO
= 10mA
V
IH
V
SHDN
= 0V to V
IN
V
SET
= 0V, V
IN
= 6V, I
OUT
= 10mA,
T
A
= -40°C to +85°C
V
SET
= 0V,
V
SHDN
= 0V,
R
DD
= 100k ,
I
OUT
= 10mA
V
SET
= 0V, V
IN
= 6V, I
OUT
= 10mA,
T
A
= -55°C to +125°C
V
nA
V
V
V
mA
µA
V
mV
mV
mV
mA
µA
mA
V
V
SHDN
= 0V,
V
SET
= 0V
V
UNITS
SHDN Threshold
0.3
0.3
V
IL
ELECTRICAL CHARACTERISTICS
(GND = 0V, V
IN
= +9V, V
OUT
= +5V, C1 = 10
µ
F, unless otherwise noted.)
V
IN
= 7V
V
IN
= 4.5V
SET Input Leakage Current
I
SET
0.01
±10
±1000
V
SET
= 1.5V
nA
Low-Battery Detector
Input Leakage Current
I
LBI
0.01
±10
±1000
V
LBI
= 1.5V
nA MAX667
+5V/Programmable Low-Dropout
Voltage Regulator
_______________________________________________________________________________________
3
1000
1
1
10
100
1000
DROPOUT VOLTAGE
vs. LOAD CURRENT
10
100
MAX667-Fg TOC 1
LOAD CURRENT (mA)
DROPOUT VOLTAGE (mV)
QUIESCENT CURRENT
vs. LOAD CURRENT
QUIESCENT CURRENT (
µ
A)
10
100
1000
10,000
100,000
0.01
0.1
1
10
100
1000
MAX667-Fg TOC 2
LOAD CURRENT (mA)
VIN = +6V
1000
1
0
50
150
250
10
100
MAX667-Fg TOC 3
100
200
DD OUTPUT CURRENT
vs. INPUT-OUTPUT DIFFERENCE
DD OUTPUT CURRENT (
µ
A)
INPUT-OUTPUT DIFFERENCE (mV)
5 10
1
20 50 100mA LOAD
2
__________________________________________Typical Operating Characteristics
_____________________Pin Description
_______________Detailed Description
Figure 1 shows a micropower bandgap reference, an
error amplifier, a PNP pass transistor, and two com-
parators as the main elements of the MAX667. One
comparator, C1, selects the fixed 5V or adjustable
operation with an external voltage divider. The other
comparator, C2, is a low-battery detector.
The bandgap reference, which is trimmed to 1.22V,
connects internally to one input of the error amplifier,
A1. The feedback signal from the regulator output sup-
plies the other input of A1 from either an on-chip volt-
age divider or two external resistors. When SET is
grounded, the internal divider provides the error ampli-
fier feedback signal for a fixed 5V output. When SET is
more than 50mV above ground, the error amplifiers
input switches directly to SET while an external resistor
divider from OUT determines the output voltage.
A second comparator, C2, compares the LBI input to
the internal reference voltage. LBO is an open-drain
FET connected to GND. The low-battery threshold can
also be set with a voltage divider at LBI. In addition, the
MAX667 has a shutdown input (SHDN) that disables
the load and the device while reducing quiescent cur-
rent when it is pulled high.
+5V Output
Figure 2 shows the connection for a fixed 5V output.
The SET input is grounded, and no external resistors
are required. Figure 3 shows adjustable output opera-
tion. R1 and R2 set the output voltage. SHDN should be
grounded if not used.
(Output) Voltage Set, CMOS Input.
Connect to GND for 5V output. For
other voltages, connect external resis-
tive divider from OUT.
SET
6
Low-Battery Output. An open-drain N-
channel transistor that sinks current to
GND when LBI is less than 1.22V.
LBO
7
Positive Input Voltage (unregulated)
IN
8
Regulated Output Voltage. OUT falls
to 0V when SHDN is above 1.5V. SET
determines output voltage when SET
is above 50mV; otherwise, it is 5V.
OUT must be connected to an output
filter capacitor.
OUT
2
Low-Battery Detector. A CMOS input
to an internal 1.255V comparator
whose output is the LBO pin.
LBI
3
Ground
GND
4
Shutdown Input. Connect to GND for
normal operation (output active). Pull
above 1.5V to disable OUT, LBO, and
DD and to reduce quiescent current to
less than 1µA.
SHDN
5
PIN
Dropout Detector Outputthe collec-
tor of a PNP pass transistor. Normally
an open circuit, it sources current as
dropout is reached.
DD
1
FUNCTION
NAME
(T
A
= +25°C, unless otherwise noted.) MAX667
+5V/Programmable Low-Dropout
Voltage Regulator
4
_______________________________________________________________________________________
SHDN
LBO
LBI
+50mV
SET
OUT
DD
GND
IN
A1
C2
C1
1.255V REF
MAX667
Figure 1. MAX667 Block Diagram
MAX667
GND
SHDN
SET
OUT
+5V OUT
250mA
IN
8
6
4
5
2
C1
10
µ
F
Figure 2. Fixed +5V Regulator
MAX667
GND
SHDN
OUT
VOUT
IN
LBO
SET
LBI
8
7
3
5
4
2
6
R2
R1
R3
R4
C1
10
µ
F
N
VREF

Figure 3. Adjustable Output and Low-Battery Detector Output-Voltage Selection
If SET is connected to a resistive voltage divider (Figure
3), the out