General Description
The MAX6765–MAX6774 are low-quiescent-current, high-
voltage linear regulators that operate from 4V to 72V and
deliver up to 100mA of load current. These low-power
devices consume only 31µA of quiescent current, making
them ideal for always-on automotive modules. These
devices are offered with fixed standard output options of
5.0V, 3.3V, 2.5V, and 1.8V, or can be adjusted from 1.8V
to 11V with two external resistors.
The MAX6765–MAX6774 feature a push-pull or open-
drain, active-low RESET output with either fixed or
adjustable thresholds. Whenever the regulator’s output
falls below the reset threshold, the RESET output asserts
and remains asserted for at least the minimum reset
timeout period after the output voltage exceeds its
threshold. The minimum reset timeout period is offered
with fixed values from 75µs to 200ms or can be adjusted
externally with a small capacitor.
These devices provide three regulator enable modes to
accommodate several power-on schemes. The
MAX6765/MAX6766/MAX6769/MAX6770/MAX6773/
MAX6774 feature a single traditional enable input
(ENABLE) to turn on and off the regulator. The
MAX6771/MAX6772 provide dual enable inputs
(ENABLE1 and ENABLE2) to turn on and off the regulator
either through an ignition switch or a bus transceiver. The
MAX6767/MAX6768 provide a hold input (HOLD) in addi-
tion to the enable input to allow for the implementation of a
self-holding circuit without requiring external components.
Setting HOLD low after enabling the regulator forces the
regulator to remain on even if ENABLE is subsequently
set low. Releasing HOLD shuts down the regulator.
The MAX6773/MAX6774 also include a watchdog input
that monitors a pulse train from the microprocessor (µP)
and generates a reset pulse if the watchdog input
remains high or low for a duration longer than the 1.6s
(typ) watchdog timeout period.
The MAX6765–MAX6774 are available in a small, ther-
mally enhanced 3mm x 3mm TDFN package that can
dissipate up to 1.951W, thereby supporting continuous
regulator operation during high ambient temperatures,
high battery voltage, and high load-current conditions.
The MAX6765–MAX6774 are fully specified for a -40°C to
+125°C operating temperature range.
Applications
Automotive
Industrial
Telecom
Features
♦ Low 31µA Quiescent Current
♦4V to 72V Wide Input Voltage Range
♦100mA Output Current Capability
♦Dropout Voltage of 620mV with 5V Output
at 100mA
♦Fixed Output-Voltage Options: 5V, 3.3V, 2.5V,
and 1.8V
♦Adjustable Output Voltages from 1.8V to 11V
♦Open-Drain or Push-Pull RESET Output
♦Fixed or Capacitor-Adjustable Reset Timeouts
♦Small, Thermally Enhanced 1.9W, 3mm x 3mm
TDFN Package
♦Overtemperature and Short-Circuit Protection
♦Fully Specified from -40°C to +125°C
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
________________________________________________________________ Maxim Integrated Products 1
1
+
23
654
ENABLE
GND
IN
RESET
TIMEOUT
OUT
MAX6765
MAX6766
TDFN
TOP VIEW
PART TEMP
RANGE
PIN-
PACKAGE
PKG
CODE
MAX6765TT_D_+ -40°C to +125°C 6 TDFN-EP* T633-2
MAX6766TT_D_+ -40°C to +125°C 6 TDFN-EP* T633-2
Pin Configurations
Ordering Information
19-0657; Rev 1; 1/07
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.
Ordering Information continued at end of data sheet.
Typical Application Circuit and Selector Guide appear at
end of data sheet. Pin Configurations continued at end of data sheet.
The first “_” is a placeholder for the voltage output and reset
threshold. The 2nd “_” designates the fixed reset-timeout option.
See Tables 1 and 2 for details. For example, the MAX6765TTLD4
has a 5V output, a reset threshold of 4.65V, and a 200ms typical
reset timeout.
+Denotes lead-free package.
*EP = Exposed paddle.
For tape-and-reel orders add a “T” after the “+” symbol to com-
plete the part number. Tape-and-reel orders are available in
2.5k increments. Nonstandard versions require a 10k minimum
order quantity.
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(VIN = 14V, CIN = 0.1µF, COUT = 10µF, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.)
(Note 1)
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.
(All pins referenced to GND, unless otherwise noted.)
VIN ..........................................................................-0.3V to +80V
OUT ................................................-0.3V to min (12V, IN + 0.3V)
ENABLE, ENABLE1, ENABLE2 .....................-0.3V to (IN + 0.3V)
RESET (open-drain output), TIMEOUT, WDI,
RESETIN, SET ......................................................-0.3V to 12V
RESET (push-pull output), HOLD ..............-0.3V to (OUT + 0.3V)
Maximum Current (all pins except IN and OUT).................50mA
Continuous Power Dissipation (TA= +70°C)
6-Pin TDFN 3mm x 3mm
(derate 23.8mW/°C above +70°C)...........................1904.8mW
8-Pin TDFN 3mm x 3mm
(derate 24.4mW/°C above +70°C)...........................1951.2mW
Operating Temperature Range .........................-40°C to +125°C
Junction Temperature......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
PARAMETER
SYMBOL
CONDITIONS MIN TYP
MAX
UNITS
Supply Voltage Range VIN 472V
ILOAD = 0 31 45
ILOAD = 50mA 35 50
ILOAD = 100mA, VIN = 14V 37 55
ILOAD = 0, VIN = 42V 35 50
Supply Current
(MAX6765–MAX6772) (Note 2)
ILOAD = 10mA, VIN = 42V 37 55
µA
ILOAD = 0 38 50
ILOAD = 50mA 42 55
ILOAD = 100mA 44 60
ILOAD = 0, VIN = 42V 42 55
Supply Current
(MAX6773/MAX6774) (Note 2)
ILOAD = 10mA, VIN = 42V 44 60
µA
Shutdown Supply Current
ISHDN
ENABLE , ENABLE1, ENABLE2 = GND 3.3 7 µA
L/M, ILOAD = 1mA
4.925
5
5.075
L/M, 1mA ≤ ILOAD ≤ 100mA, VIN = 11V
4.850
5
5.150
T/S, ILOAD = 1mA
3.251
3.3
3.350
T/S, 1mA ≤ ILOAD ≤ 100mA, VIN = 9.3V
3.201
3.3
3.399
Z/Y, ILOAD = 1mA
2.463
2.5
2.538
Z/Y, 1mA ≤ ILOAD ≤ 100mA, VIN = 8.5V
2.425
2.5
2.575
W/V, ILOAD = 1mA
1.773
1.8
1.827
Output Voltage VOUT
W/V, 1mA ≤ ILOAD ≤ 100mA, VIN = 7.8V
1.746
1.8
1.854
V
Adjustable Output Voltage Range
VOUT 1.8 11.0 V
SET Threshold Voltage
(MAX6767–MAX6774) VSET ILOAD = 1mA 1.20
1.233
1.26 V
SET rising 116
Dual Mode™ SET Threshold SET falling 58 mV
Dual Mode is a trademark of Maxim Integrated Products, Inc.
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
_______________________________________________________________________________________ 3
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 14V, CIN = 0.1µF, COUT = 10µF, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS MIN TYP
MAX
UNITS
SET Input Current
(MAX6767–MAX6774) ISET VSET = 1.5V, VIN = 11V -100
+100
nA
L/M, 5V output option, ILOAD = 10mA 60 130
L/M, 5V output option, ILOAD = 50mA 300 630
L/M, 5V output option, ILOAD = 100mA 620
1200
Dropout Voltage (Note 3) ∆VDO
T/S, 3.3V output option, ILOAD = 100mA 866
1600
mV
Guaranteed Output Current
(Note 4) 100 mA
Output Current Limit Output shorted to GND, VIN = 14V 150 250 mA
Thermal-Shutdown Temperature 160 °C
Thermal-Shutdown Hysteresis 20 °C
Line Regulation 6.5V ≤ VIN ≤ 72V, ILOAD = 1mA 1 %
Load Regulation
(MAX6767–MAX6774)
IOUT = 1mA to 100mA,
VIN = VOUT(NOM) + 6V 1.5 %
Power-Supply Rejection Ratio PSRR ILOAD = 10mA, fIN = 100Hz, 500mVP-P 70 dB
Startup Response Time
tSTART
From ENABLE high to OUT,
ILOAD = 100mA 180 µs
Output Overvoltage Protection
Threshold OVTH ISINK = 1mA (from OUT) 1.07 x
VOUT
1.1 x
VOUT
1.13 x
VOUT
V
Output Overvoltage Protection
Maximum Sink Current OUT = OUT(NOM) x 1.15 5 10 mA
LOGIC INPUT (ENABLE, ENABLE1, ENABLE2, HOLD)
Input Low Voltage VIL ENABLE, ENABLE1, ENABLE2 0.4 V
Input High Voltage VIH ENABLE, ENABLE1, ENABLE2 1.4 V
ENABLE, ENABLE1, ENABLE2
Input Pulldown Current
ENABLE, ENABLE1, ENABLE2 are
internally pulled down to GND 0.6 µA
VIL 1.8V ≤ VOUT ≤ 11V 0.4
HOLD Input Threshold Voltage VIH 1.8V ≤ VOUT ≤ 11V OUT -
0.4
V
HOLD Input Pullup Current HOLD is internally pulled up to OUT 1.8 µA
RESET OUTPUT
L
4.500 4.625 4.750
M
4.250 4.375 4.500
T
2.970 3.053 3.135
S
2.805 2.888 2.970
Z
2.250 2.313 2.375
Y
2.125 2.188 2.250
W
1.620 1.665 1.710
RESET Threshold SET = GND,
RESET falling
V
1.530 1.575 1.620
V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(VIN = 14V, CIN = 0.1µF, COUT = 10µF, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at TA= TJ= +25°C.)
(Note 1)
PARAMETER
SYMBOL
CONDITIONS MIN TYP
MAX
L/T/Z/W, SET = resistive divider, RESET
falling
VOUT x
0.9
VOUT x
0.925
VOUT x
0.950
RESET Threshold (Adjustable
Output Voltage) M/S/Y/V, SET = resistive divider, RESET
falling
VOUT x
0.85
VOUT x
0.875
VOUT x
0.900
V
RESETIN Input Current RESETIN = GND or 12V -100
+100
nA
VTH = 87.5% of VSET (M/S/Y/V),
RESET falling
1.057 1.085 1.112
RESETIN Threshold
VTH = 92.5% of VSET (L/T/Z/W),
RESET falling
1.118 1.147 1.176
V
OUT to RESET Delay VOUT falling 0.3 µs
RESETIN To RESET Delay RESETIN falling 35 µs
D0 75 µs
D1
2.187 3.125 4.063
D2 8.75 12.5
16.25
D3 35 50 65
RESET Timeout Period (TIMEOUT
Connected to OUT) VOUT rising
D4 140 200 260
ms
TIMEOUT Ramp Current 800
1000 1200
nA
TIMEOUT Ramp Threshold
1.160
1.22
1.259
V
VOUT ≥ 1.8V, ISINK = 50µA,
RESET asserted 0.3
RESET Output-Voltage Low
(Open Drain or Push-Pull) VOL VOUT ≥ 1.8V, ISINK = 3.2mA,
RESET asserted 0.4
V
RESET Output-Voltage High
(Push-Pull) VOH VOUT ≥ 1.8V, ISOURCE = 250µA,
RESET not asserted
0.8 x
VOUT
V
RESET Open-Drain Leakage
Current RESET not asserted, RESET = 12V 100 nA
Watchdog Minimum Input Pulse tWDI 1.8V ≤ VOUT ≤ 11V 1 µs
Watchdog Input Low Voltage VIL 1.8V ≤ VOUT ≤ 11V 0.4 V
Watchdog Input High Voltage VIH 1.8V ≤ VOUT ≤ 11V
VOUT
- 0.4V
V
Watchdog Input Low Voltage VIL 1.8V ≤ VOUT ≤ 11V 0.4 V
Watchdog Input Current IWDI WDI = 0V or WDI = 12V -1 +1 µA
Watchdog Timeout Period tWD 1.12 1.6 2.08 s
Note 1: Production tested at TA= +25°C. Overtemperature limits are guaranteed by design.
Note 2: Device tested at internally set voltage.
Note 3: Dropout voltage for L/M versions is defined as (VIN - VOUT) when VOUT equals 98% of the nominal value of VOUT when
VIN = 11V. For T/S versions, dropout voltage is defined as (VIN - VOUT) when VOUT equals 98% of the nominal value of VOUT
when VIN = 9.3V.
Note 4: Observe the absolute maximum power dissipation limits.
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
_______________________________________________________________________________________ 5
24
28
26
32
30
36
34
38
42
40
44
4202812 36 44 52 60 68
SUPPLY CURRENT vs. INPUT VOLTAGE
MAX6765 toc01
INPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
ILOAD = 100mA
ILOAD = 0
LIMITED BY POWER
DISSIPATION
VOUT = 3.3V
27
31
29
37
35
33
39
41
45
43
47
-40 -10 5-25 203550658095110125
SUPPLY CURRENT vs. TEMPERATURE
MAX6765 toc02
TEMPERATURE (°C)
SUPPLY CURRENT (µA)
ILOAD = 100mA
ILOAD = 50mA
ILOAD = 1mA
ILOAD = 0
VOUT = 5V
1.0
1.5
4.5
2.5
2.0
3.0
3.5
4.0
5.0
-40 -10 5 20-25 35 50 9580 11065 125
SHUTDOWN SUPPLY CURRENT
vs. TEMPERATURE
MAX6765 toc03
TEMPERATURE (°C)
SHUTDOWN SUPPLY CURRENT (µA)
0
1.0
0.5
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
12 36 60
SHUTDOWN SUPPLY CURRENT
vs. INPUT VOLTAGE
MAX6765 toc04
INPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
428445220 68
0.992
1.004
1.003
1.002
1.001
1.000
0.999
0.998
0.997
0.996
0.995
0.994
0.993
-40 -10 5-25 203550658095110125
NORMALIZED RESETIN THRESHOLD VOLTAGE
vs. TEMPERATURE
MAX6765 toc05
TEMPERATURE (°C)
NORMALIZED RESETIN THRESHOLD VOLTAGE
20
0
100
50
150
200
250
300
350
400
450
500
550
600
40 60 80 100
DROPOUT VOLTAGE
vs. LOAD CURRENT
MAX6765 toc06
LOAD CURRENT (mA)
DROPOUT VOLTAGE (mV)
03010 50 70 90
VOUT = 5V
4.80
4.90
4.85
4.95
5.10
5.15
5.05
5.00
5.20
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX6765 toc07
OUTPUT VOLTAGE (V)
20 40 60 80 100
LOAD CURRENT (mA)
03010 50 70 90
VOUT = 5V
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX6765 toc08
3.22
3.20
3.24
3.30
3.32
3.28
3.26
3.34
OUTPUT VOLTAGE (V)
20 40 60 80 100
LOAD CURRENT (mA)
03010 50 70 90
VOUT = 3.3V
Typical Operating Characteristics
(VIN = 14V, COUT = 10µF, CIN = 0.1µF, TA= +25°C, unless otherwise noted.)
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VIN = 14V, COUT = 10µF, CIN = 0.1µF, TA= +25°C, unless otherwise noted.)
OUTPUT VOLTAGE
vs. LOAD CURRENT
MAX6765 toc09
OUTPUT VOLTAGE (V)
1.79
1.77
1.76
1.75
1.78
1.80
1.83
1.84
1.82
1.81
1.85
20 40 60 80 100
LOAD CURRENT (mA)
03010 50 70 90
VOUT = 1.8V
0
20
40
60
80
100
120
140
160
0 25 50 75 100 125
RESET TIMEOUT PERIOD
vs. CAPACITOR VALUE
MAX6765 toc10
CAPACITOR VALUE (nF)
RESET TIMEOUT PERIOD (ms)
0.94
0.96
1.08
1.00
0.98
1.02
1.04
1.06
1.10
-40 -10 5 20-25 35 50 9580 11065 125
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
MAX6765 toc11
TEMPERATURE (°C)
NORMALIZED RESET TIMEOUT PERIOD
NORMALIZED WATCHDOG TIMEOUT
vs. TEMPERATURE
MAX6765 toc12
0.90
0.92
1.04
0.96
0.94
0.98
1.00
1.02
1.06
-40 -10 5 20-25 35 50 9580 11065 125
TEMPERATURE (°C)
NORMALIZED WATCHDOG TIMEOUT
0
1.0
0.5
2.0
1.5
2.5
3.0
3.5
4.0
010155 2025303540
RESET OUTPUT vs. SINK CURRENT
MAX6765 toc13
SINK CURRENT (mA)
RESET OUTPUT (V)
VOUT = 5V
0
0
1.0
0.5
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
4 8 12 16
MAX6765 toc14
SOURCE CURRENT (mA)
RESET OUTPUT (V)
621014
RESET OUTPUT vs. SOURCE CURRENT
VOUT = 5V
34
35
36
37
38
39
40
41
42
0.001 0.01 0.1 1 10 100
SUPPLY CURRENT
vs. WATCHDOG INPUT FREQUENCY
MAX6765 toc15
WATCHDOG INPUT FREQUENCY (kHz)
SUPPLY CURRENT (µA)
VOUT = 5V
ENABLE
5V/div
GATE
5V/div
HOLD
5V/div
OUT
5V/div
OUT AND HOLD vs. ENABLE
MAX6765 toc16
20ms/div
(SEE TEST CIRCUIT FOR ENABLE AND HOLD)
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
_______________________________________________________________________________________ 7
-180
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
POWER-SUPPLY REJECTION RATIO
vs. FREQUENCY
FREQUENCY (Hz)
0.1 1k 10k 100k101 100 1M
POWER-SUPPLY REJECTION RATIO (dB)
MAX6765 toc17
0.9980
0.9990
0.9985
1.0000
0.9995
1.0005
1.0010
1.0015
1.0020
4202812 36 44 52 60 68
NORMALIZED OUT VOLTAGE
vs. INPUT VOLTAGE
MAX6765 toc18
INPUT VOLTAGE (V)
NORMALIZED OUT VOLTAGE
VOUT = 3.3V
OUT
(AC-COUPLED)
200mV/div
IOUT
100mA/div
LOAD-TRANSIENT RESPONSE
MAX6765 toc19
100ms/div
VOUT = 5V
OUT
(AC-COUPLED)
1V/div
VIN
10V/div
LINE-TRANSIENT RESPONSE
MAX6765 toc20
400µs/div
VOUT = 5V
OUT
(AC-COUPLED)
1V/div
VIN
20V/div
LINE-TRANSIENT RESPONSE
MAX6765 toc21
400µs/div
VOUT = 5V
0
2
1
3
4
5
6
7
8
9
10
11
40 80
SERIES RESISTANCE vs. LOAD CURRENT
MAX6765 toc22
LOAD CURRENT (mA)
SERIES RESISTANCE (Ω)
06020 100
STABLE OPERATING
REGION
Typical Operating Characteristics (continued)
(VIN = 14V, COUT = 10µF, CIN = 0.1µF, TA= +25°C, unless otherwise noted.)
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
8 _______________________________________________________________________________________
Pin Description
Enable and Hold Test Circuit
PIN
MAX6765/
MAX6766
MAX6767/
MAX6768
MAX6769/
MAX6770
MAX6771/
MAX6772
MAX6773/
MAX6774
NAME
FUNCTION
11111IN
Regulator Input. Bypass IN to GND with a capacitor
with a minimum value of 0.1µF.
2 2 2 2 2 GND Ground
333—3
ENABLE
Active-High Enable Input. Drive ENABLE high to turn on
the regulator. ENABLE is internally connected to GND
through a 0.6µA current sink.
45555
RESET
Active-Low, Open-Drain/Push-Pull Reset Output.
For the MAX6769/MAX6770, RESET asserts when
RESETIN is below the internal VTH and deasserts when
RESETIN is above the internal VTH threshold.
For all other versions, RESET remains low while OUT is
below the reset threshold. For all versions, RESET
remains low for the duration of the reset timeout period
after the reset conditions end.
57777
TIMEOUT
Reset Timeout Adjust Input. Connect TIMEOUT to OUT
for the internally fixed timeout period. For an adjustable
timeout, connect a capacitor from TIMEOUT to GND.
See the Selecting Timeout Capacitor section.
6 8 8 8 8 OUT
Regulator Output. The MAX6765/MAX6766 provide
a fixed output (+1.8V, +2.5V, +3.3V, or +5V). The
MAX6767–MAX6774 provide a fixed output voltage
of +1.8V, +2.5V, +3.3V, or 5V, or adjust the output from
+1.8V to +11V. Bypass to GND with a 10µF capacitor
(min).
GND
VIN
IN
ENABLE
N
ENABLE
GATE
HOLD
OUT
OUT
MAX6767
MAX6768
TEST CIRCUIT FOR OUT AND HOLD VS. ENABLE
HOLD
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
_______________________________________________________________________________________ 9
Pin Description (continued)
PIN
MAX6765/
MAX6766
MAX6767/
MAX6768
MAX6769/
MAX6770
MAX6771/
MAX6772
MAX6773/
MAX6774
NAME
FUNCTION
—4———HOLD
Active-Low Regulator Hold Input. When HOLD is forced
low, OUT remains on even if ENABLE is pulled low. To
shut down the regulator, release HOLD after ENABLE is
pulled low. Connect HOLD to OUT or leave
unconnected if unused. HOLD is internally connected
to OUT through a 1.8µA current source.
— 6 6 6 6 SET
Feedback Input for Setting the Output Voltage. Connect
SET to GND to select the preset output voltage.
Connect to an external resistive divider for
adjustable output operation.
—— 4——
RESETIN
Adjustable Reset Threshold Input. Connect to a
resistive divider to set the desired threshold.
———3—
ENABLE1
Active-High Enable Input 1. Drive ENABLE1 high to turn
on the regulator. ENABLE1 is internally connected to
ground through a 0.6µA current sink.
———4—
ENABLE2
Active-High Enable Input 2. Drive ENABLE2 high to turn
on the regulator. ENABLE2 is internally connected to
ground through a 0.6µA current sink.
————4WDI
Watchdog Timer Input. If WDI remains high or low for
longer than the watchdog timeout period, the
internal watchdog timer expires and the reset output
asserts for the reset timeout period. The internal
watchdog timer clears whenever a reset is asserted or
WDI sees a rising or falling edge. The watchdog timer
cannot be disabled. Do not leave WDI unconnected.
EP EP EP EP EP —
Exposed Paddle. EP is internally connected to GND.
Connect EP to the ground plane to provide a low
thermal-resistance path from the IC junction to the PCB.
Do not use as the electrical connection to GND.
Detailed Description
The MAX6765–MAX6774 low-quiescent-current, high-
voltage linear regulators operate from a 4V to 72V input
voltage and deliver more than 100mA of load current.
The MAX6765–MAX6774 include an integrated µP reset
circuit that monitors the regulator output voltage and
asserts a reset output when OUT falls below a threshold
limit, and includes an internally fixed or adjustable reset
timeout using a capacitor from TIMEOUT to ground. All
devices are available in a preset output-voltage option of
+1.8V, +2.5V, +3.3V, and +5V. The output voltage of the
MAX6767–MAX6774 is adjustable from +1.8V to +11V
using a resistive divider at SET. The MAX6773/MAX6774
include a watchdog timer (WDI) with a 1.6s (typ) watch-
dog timeout period. The MAX6769/MAX6770 feature an
adjustable reset threshold using a resistive divider
between the monitored voltage, RESETIN, and GND; see
the Functional Diagrams.
The MAX6771/MAX6772 provide dual enable inputs
(ENABLE1 and ENABLE2) to turn on and off the regula-
tor either through an ignition switch or a bus transceiver.
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
10 ______________________________________________________________________________________
Functional Diagrams
MAX6765/MAX6766
THERMAL
PROTECTION
CONTROL
LOGIC
1.233V
OUT
RESET
GND
1.147V
OR
1.085V
OVERCURRENT
PROTECTION
RESET
TIMEOUT
IN
ENABLE
TIMEOUT
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 11
Functional Diagrams (continued)
MAX6767/MAX6768
THERMAL
PROTECTION
CONTROL
LOGIC
116mV
OUT
SET
RESET
GND
OVERCURRENT
PROTECTION
RESET
TIMEOUT
IN
ENABLE
HOLD
TIMEOUT
1.233V
1.147V
OR
1.085V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
12 ______________________________________________________________________________________
Functional Diagrams (continued)
MAX6769/MAX6770
THERMAL
PROTECTION
CONTROL
LOGIC
116mV
OUT
SET
RESET
GND
OVERCURRENT
PROTECTION
RESET
TIMEOUT
RESETIN
IN
ENABLE
TIMEOUT
1.233V
1.147V
OR
1.085V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 13
Functional Diagrams (continued)
MAX6771/MAX6772
THERMAL
PROTECTION
CONTROL
LOGIC
OUT
RESET
GND
OVERCURRENT
PROTECTION
RESET
TIMEOUT
IN
ENABLE1
TIMEOUT
ENABLE2
116mV
SET
1.233V
1.147V
OR
1.085V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
14 ______________________________________________________________________________________
Functional Diagrams (continued)
MAX6773/MAX6774
THERMAL
PROTECTION
CONTROL
LOGIC
OUT
RESET
GND
OVERCURRENT
PROTECTION
RESET
TIMEOUT
IN
ENABLE
TIMEOUT WDI
116mV
SET
1.233V
1.147V
OR
1.085V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 15
Regulator
The regulator accepts an input voltage from +4V to +72V.
All of the devices feature fixed output-voltage options of
+1.8V, +2.5V, +3.3V, and +5V. The MAX6767–MAX6774
feature an adjustable output voltage set with an external
resistive-divider network connected between OUT, SET,
and GND. See Figure 1.
Enable and Hold Inputs
(MAX6767/MAX6768)
The MAX6767/MAX6768 support two logic inputs,
ENABLE (active-high) and HOLD (active-low), making
these devices “automotive friendly.” For example, when
the ignition key signal drives ENABLE high, the regulator
turns on and remains on even if ENABLE goes low, as
long as HOLD is forced low and kept low before
ENABLE goes low. In this state, releasing HOLD turns
the regulator output (OUT) off. This feature makes it pos-
sible to implement a self-holding circuit without external
components. Forcing ENABLE low with HOLD high (or
unconnected) places the MAX6767/MAX6768 into shut-
down mode, drawing 3.3µA (typ) of supply current.
Table 3 shows the state of the regulator output with
respect to the voltage level at ENABLE and HOLD.
Connect HOLD to OUT or leave it unconnected to allow
the ENABLE input to act as a standard enable/shut-
down switch for the regulator output (OUT).
Reset Output
The reset output is typically connected to the reset
input of a µP. A µP’s reset input starts or restarts the µP
in a known state. The MAX6765–MAX6774 supervisory
circuits provide the reset logic to prevent code-execu-
tion errors during power-up, power-down, and
brownout conditions (see the Typical Application
Circuit). RESET changes from high to low whenever the
monitored voltage drops below the reset threshold volt-
ages. Once the monitored voltage exceeds its respec-
tive reset threshold voltage(s), RESET remains low for
the reset timeout period, then goes high. See Table 1.
RESETIN Threshold (MAX6769/MAX6770)
The MAX6769/MAX6770 monitor the voltage on RESETIN
using an adjustable reset threshold (VRESETIN) set with
an external resistive voltage-divider and the internal reset
threshold VTH. See Table 2.
MAX6767–MAX6774
SET
R1
R2
GND
IN
VIN
OUT
Figure 1. Setting the Output Voltage Using a Resistive Divider
PART NUMBER
SUFFIX (_)
OUTPUT
VOLTAGE (V)
RESET
THREHOLD (V)
L 5 4.625
M 5 4.375
T 3.3 3.053
S 3.3 2.888
Z 2.5 2.313
Y 2.5 2.188
W 1.8 1.665
V 1.8 1.575
Table 2. Preset Output Voltage and Reset
Threshold
PART NUMBER
SUFFIX (_)
TIMEOUT
PERIOD
D0 75µs
D1 3.125ms
D2 12.5ms
D3 50ms
D4 200ms
Table 1. Preset Timeout Period
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
16 ______________________________________________________________________________________
Watchdog Timer (MAX6773/MAX6774)
The MAX6773/MAX6774 include a watchdog timer that
asserts RESET if the watchdog input (WDI) does not
toggle within the watchdog timeout period tWD (1.6s,
typ). RESET remains low for the reset timeout period,
tRP. If the watchdog is not updated for lengthy periods
of time, the reset output appears as a pulse train,
asserted for the reset timeout period and deasserted
for the watchdog timeout period, until WDI is toggled
again. When RESET asserts, it stays low for the entire
reset timeout period ignoring any WDI transitions. To
prevent the watchdog from asserting RESET, toggle
WDI with a valid rising or falling edge prior to tWD (min)
= 1.12s. The watchdog counter clears when WDI tog-
gles prior to tWD or when RESET asserts. The watchdog
resumes counting after RESET deasserts. The watch-
dog timer cannot be disabled.
Thermal Protection
When the junction temperature exceeds TJ= +160°C
(typ), an internal thermal sensor signals the shutdown
logic that turns off the pass transistor and allows the IC
to cool. The thermal sensor turns the pass transistor on
again after the IC’s junction temperature cools by 20°C
(typ), resulting in a cycled output during continuous
thermal-overload conditions. Thermal protection pro-
tects the MAX6765–MAX6774 in the event of a fault con-
dition. Never exceed the absolute maximum junction
temperature rating of TJ= +150°C. See Figures 3 and 4
for the safe operating area.
Applications Information
Output Voltage Selection
The MAX6767–MAX6774 feature dual-mode operation:
these devices operate in either a preset or adjustable
voltage mode. In preset voltage mode, internal trimmed
feedback resistors set the internal linear regulator to
+1.8V, +2.5V, +3.3V, or +5V (see Table 2). Select pre-
set-voltage mode by connecting SET to ground. In
adjustable mode, select an output voltage between
+1.8V and +11V using two external resistors connected
as a voltage-divider to SET (see Figure 1). Set the out-
put voltage using the following equation:
VOUT = VSET (1 + R1 / R2)
where VSET = 1.233V and the recommended value for
R2 is 50kΩ(maximum 100kΩ).
RESETIN Threshold Selection
The MAX6769/MAX6770 feature an adjustable reset
threshold to monitor the voltage on RESETIN using a
resistive divider between the monitored voltage,
RESETIN and GND. See Figure 2. Use the following for-
mula to set the desired reset threshold:
VMON = VTH (1 + R3 / R4)
where VTH is 1.085V for the M/S/Y/V versions and
1.147V for L/T/Z/W versions.
MAX6769
MAX6770
RESETRESETIN
R3
R4 GND
IN
VIN
VMON
Figure 2. RESETIN Threshold Selection
OPERATING
STATE
ENABLE
HOLD
REGULATOR
OUTPUT COMMENT
Initial State Low
Don’t care
Off ENABLE is pulled to GND through an internal pulldown. HOLD is
floating (pulled up to OUT). Regulator output is disabled.
Turn-On State
High
Don’t care
On ENABLE is externally driven high turning the regulator output on.
HOLD is pulled up by OUT.
Hold
Setup State High Low On HOLD is externally pulled low while ENABLE remains high (latches
HOLD state).
Hold State Low Low On ENABLE is driven low (or allowed to float low by an internal pulldown).
HOLD remains externally pulled low keeping the regulator output on.
Off-State Low High
(floats high)
Off
HOLD is driven high (or allowed to float high by an internal pullup)
while ENABLE is low. Regulator output is shut off and ENABLE/
HOLD logic returns to the initial state.
Table 3. ENABLE/HOLD Truth Table/State Table
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 17
Available Output-Current Calculation
The MAX6765–MAX6774 provide up to 100mA of load
current. Package power dissipation limits the amount of
output current available for a given input/output voltage
and ambient temperature. Figures 3 and 4 depict the
maximum power dissipation curve for the MAX6765/
MAX6766 and MAX6767–MAX6774, respectively. The
graph assumes that the exposed metal pad of the
device package is soldered to a solid 1in2section of
2oz. PCB copper (JESD51-3 AND JESD51-5). Use
Figure 4 to determine the allowable package dissipa-
tion for a given ambient temperature. Alternately, use
the following formula to calculate the allowable pack-
age dissipation:
PDMAX = Max. Power Dissip = 1.951W, for TA≤+70°C
PDMAX = Max. Power Dissip = [1.9W - 0.0244W x
(TA- 70°C)], for +70°C < TA≤+125°C
where 0.0244W is the MAX6767–MAX6774 package
thermal derating in W/°C and TAis the ambient tempera-
ture in °C, under the same conditions used for Figure 4.
After determining the allowable package dissipation,
calculate the maximum output current using the follow-
ing formula:
PD < PDMAX where PD = [(VIN - VOUT) x IOUT]
Also, IOUT should be ≤100mA in any case.
Selecting Timeout Capacitor
The reset timeout period is adjustable to accommodate
a variety of µP applications. Adjust the reset timeout
period by connecting a capacitor between TIMEOUT
and GND.
tRP = CTIMEOUT x 1.22 x 106Ω
where tRP is in seconds and CTIMEOUT is in Farads.
Connect TIMEOUT to OUT to select the internally fixed
timeout period. CTIMEOUT must be a low-leakage
(< 10nA) type capacitor. Ceramic capacitors are rec-
ommended; do not use capacitor values lower than
100pF to avoid the influence of parasitic capacitances.
Capacitor Selection and
Regulator Stability
For stable operation over the full temperature range and
with load currents up to 100mA, use a 10µF (min) output
capacitor with an ESR < 0.5Ω. To reduce noise and
improve load-transient response, stability, and power-
supply rejection, use larger output-capacitor values.
Some ceramic dielectrics exhibit large capacitance
and ESR variation with temperature. For dielectric
capacitors such as Z5U and Y5V, use more capaci-
tance to ensure stability at low temperatures. With X7R
or X5R dielectrics, 10µF should be sufficient at all oper-
ating temperatures. For higher-ESR tantalum capaci-
tors, use larger capacitor values to maintain stability. To
improve power-supply rejection and transient
response, use a larger capacitor than the minimum
0.1µF capacitor between IN and GND.
MAX6765 fig03
TEMPERATURE (°C)
PD (W)
14012080 10040 6020
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
0
0 160
DERATE 23.8mW/°C
ABOVE +70°C
1.904W
SAFE OPERATING
AREA
MAX6765 fig04
TEMPERATURE (°C)
PD (W)
14012080 10040 6020
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
0
0 160
DERATE 24.4mW/°C
ABOVE +70°C
1.951W
SAFE OPERATING
AREA
Figure 3. Maximum Power Dissipation vs. Temperature
(MAX6765/MAX6766)
Figure 4. Maximum Power Dissipation vs. Temperature
(MAX6767–MAX6774)
MAX6765–MAX6774
Ensuring a Valid
RESET
Output Down to
VIN = 0V (MAX6766/MAX6768/MAX6770/
MAX6772/MAX6774)
When VIN falls below 1V, RESET current-sinking capa-
bilities decline drastically. High-impedance CMOS-
logic inputs connected to RESET can drift to
undetermined voltages. This presents no problems in
most applications, since most µPs and other circuitry
do not operate with supply voltages below 1V. In those
applications where RESET must be valid down to 0V,
adding a pulldown resistor between RESET and ground
sinks any stray leakage currents, holding RESET low
(Figure 5). The value of the pulldown resistor is not criti-
cal; 100kΩis large enough not to load RESET and
small enough to pull RESET to ground. Open-drain
RESET versions are not recommended for applications
requiring valid logic for VIN down to 0V.
Automotive Micropower Linear Regulators
with Supervisor
18 ______________________________________________________________________________________
PART OUTPUT
VOLTAGE (V)
RESET TIMEOUT
PERIOD (ms)
RESET THRESHOLD
(V) TOP MARK
MAX6765TTLD2+T 5 12.5 4.625 +AQB
MAX6765TTSD2+T 3.3 12.5 2.888 +AQL
MAX6766TTLD2+T 5 12.5 4.625 +ARO
MAX6766TTSD2+T 3.3 12.5 2.888 +ARZ
MAX6767TALD2+T 5 12.5 4.625 +AVI
MAX6767TASD2+T 3.3 12.5 2.888 +AVS
MAX6768TALD2+T 5 12.5 4.625 +AVZ
MAX6768TASD2+T 3.3 12.5 2.888 +AXE
MAX6769TALD2+T 5 12.5 4.625 +AYH
MAX6769TASD2+T 3.3 12.5 2.888 +AYQ
MAX6770TALD2+T 5 12.5 4.625 +AZS
MAX6770TASD2+T 3.3 12.5 2.888 +BAC
MAX6771TALD2+T 5 12.5 4.625 +BEG
MAX6771TASD2+T 3.3 12.5 2.888 +BEQ
MAX6772TALD2+T 5 12.5 4.625 +APY
MAX6772TASD2+T 3.3 12.5 2.888 +BGC
MAX6773TALD2+T 5 12.5 4.625 +BBG
MAX6773TASD2+T 3.3 12.5 2.888 +AQE
MAX6774TALD2+T 5 12.5 4.625 +BCS
MAX6774TASD2+T 3.3 12.5 2.888 +BDC
Table 4. Standard Version Part Numbers
MAX6766
MAX6768
MAX6770
MAX6772
MAX6774
RESET
GND
IN
VIN
Figure 5. Ensuring
RESET
Valid to VIN = 0V
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 19
PART RESET
OUTPUT
WATCHDOG
INPUT
OUTPUT
VOLTAGE
RESETIN
THRESHOLD
ENABLE
INPUTS
HOLD INPUT
MAX6765 Open drain — Fixed — Single —
MAX6766 Push-pull — Fixed — Single —
MAX6767 Open drain — Fixed/Adj — Single √
MAX6768 Push-pull — Fixed/Adj — Single √
MAX6769 Open drain — Fixed/Adj √Single —
MAX6770 Push-pull — Fixed/Adj √Single —
MAX6771 Open drain — Fixed/Adj — Dual —
MAX6772 Push-pull — Fixed/Adj — Dual —
MAX6773 Open drain √Fixed/Adj — Single —
MAX6774 Push-pull √Fixed/Adj — Single —
Selector Guide
MAX6766
12V
BATTERY
VCC
I/O
LIN
IN
GND
TIMEOUT
RESET
OUT
ENABLE
µC XCVR
TXD
RXD
RESET
Typical Application Circuit
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
20 ______________________________________________________________________________________
1
+
34
865
OUT
SET
RESET
MAX6767
MAX6768
2
7
TIMEOUT
ENABLE
GND
IN
HOLD
TDFN
TOP VIEW
1
+
34
865
OUT
SET
RESET
MAX6769
MAX6770
2
7
TIMEOUT
ENABLE
GND
IN
RESETIN
TDFN
TOP VIEW
1
+
34
865
OUT
SET
RESET
MAX6771
MAX6772
2
7
TIMEOUT
ENABLE1
GND
IN
ENABLE2
TDFN
TOP VIEW
1
+
34
865
OUT
SET
RESET
MAX6773
MAX6774
2
7
TIMEOUT
ENABLE
GND
IN
WDI
TDFN
TOP VIEW
Pin Configurations (continued)
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
______________________________________________________________________________________ 21
Chip Information
PROCESS: BiCMOS
PART TEMP
RANGE
PIN-
PACKAGE
PKG
CODE
MAX6767TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6768TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6769TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6770TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6771TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6772TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6773TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
MAX6774TA_D_+
-40°C to +125°C 8 TDFN-EP*
T833-2
Ordering Information (continued)
The first “_” is a placeholder for the voltage output and reset
threshold. The 2nd “_” designates the fixed reset-timeout option.
See Tables 1 and 2 for details. For example, the MAX6765TTLD4
has a 5V output, a reset threshold of 4.65V, and a 200ms typical
reset timeout.
+Denotes lead-free package.
*EP = Exposed paddle.
For tape-and-reel orders add a “T” after the “+” symbol to com-
plete the part number. Tape-and-reel orders are available in
2.5k increments. Nonstandard versions require a 10k minimum
order quantity.
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
22 ______________________________________________________________________________________
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
6, 8, &10L, DFN THIN.EPS
H
12
21-0137
PACKAGE OUTLINE, 6,8,10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
MAX6765–MAX6774
Automotive Micropower Linear Regulators
with Supervisor
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 23
© 2007 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
COMMON DIMENSIONS
SYMBOL MIN. MAX.
A 0.70 0.80
D 2.90 3.10
E 2.90 3.10
A1 0.00 0.05
L 0.20 0.40
PKG. CODE N D2 E2 eJEDEC SPEC b[(N/2)-1] x e
PACKAGE VARIATIONS
0.25 MIN.k
A2 0.20 REF.
2.30±0.101.50±0.106T633-1 0.95 BSC MO229 / WEEA 1.90 REF0.40±0.05
1.95 REF0.30±0.050.65 BSC2.30±0.108T833-1
2.00 REF0.25±0.050.50 BSC2.30±0.1010T1033-1
2.40 REF0.20±0.05- - - - 0.40 BSC1.70±0.10 2.30±0.1014T1433-1
1.50±0.10
1.50±0.10
MO229 / WEEC
MO229 / WEED-3
0.40 BSC - - - - 0.20±0.05 2.40 REFT1433-2 14 2.30±0.101.70±0.10
T633-2 6 1.50±0.10 2.30±0.10 0.95 BSC MO229 / WEEA 0.40±0.05 1.90 REF
T833-2 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF
T833-3 8 1.50±0.10 2.30±0.10 0.65 BSC MO229 / WEEC 0.30±0.05 1.95 REF
-DRAWING NOT TO SCALE-
H
22
21-0137
PACKAGE OUTLINE, 6,8,10 & 14L,
TDFN, EXPOSED PAD, 3x3x0.80 mm
2.30±0.10 MO229 / WEED-3 2.00 REF0.25±0.05
0.50 BSC
1.50±0.1010T1033-2
Revision History
Pages changed at Rev 1: 1, 21, 23