MAX6768TASD3+T Maxim Integrated Products, MAX6768TASD3+T Datasheet - Page 16
![IC REG LINEAR 3.3V/ADJ 8-TDFN](/photos/1/38/13897/8-tdfn_21-0137i_sml.jpg)
MAX6768TASD3+T
Manufacturer Part Number
MAX6768TASD3+T
Description
IC REG LINEAR 3.3V/ADJ 8-TDFN
Manufacturer
Maxim Integrated Products
Type
Regulator/Supervisorr
Datasheet
1.MAX6765TTSD2T.pdf
(22 pages)
Specifications of MAX6768TASD3+T
Number Of Voltages Monitored
1
Output
Push-Pull, Totem Pole
Reset
Active Low
Reset Timeout
35 ms Minimum
Voltage - Threshold
2.888V
Operating Temperature
-40°C ~ 125°C
Mounting Type
Surface Mount
Package / Case
8-TDFN Exposed Pad
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Automotive Micropower Linear Regulators
with Supervisor
Table 3. ENABLE/HOLD Truth Table/State Table
The MAX6773/MAX6774 include a watchdog timer that
asserts RESET if the watchdog input (WDI) does not
toggle within the watchdog timeout period t
(typ) for the MAX6773/MAX6774 and 50ms (typ) for the
MAX6773B/MAX6774B). RESET remains low for the
reset timeout period, t
ed 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 t
WDI toggles prior to t
watchdog resumes counting after RESET deasserts.
The watchdog timer cannot be disabled.
When the junction temperature exceeds T
(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–MAX6774B in the event of a fault
condition. Never exceed the absolute maximum junction
temperature rating of T
for the safe operating area.
The MAX6767–MAX6774B feature dual-mode operation:
these devices operate in either a preset or adjustable
16
Initial State
Turn-On State
Hold
Setup State
Hold State
Off-State
OPERATING
STATE
______________________________________________________________________________________
Watchdog Timer (MAX6773/MAX6773B/
WD
(min). The watchdog counter clears when
Applications Information
ENABLE
High
High
Low
Low
Low
RP
WD
J
Output Voltage Selection
= +150°C. See Figures 3 and 4
. If the watchdog is not updat-
or when RESET asserts. The
(floats high)
Don’t care
Don’t care
MAX6774/MAX6774B)
HOLD
High
Low
Low
Thermal Protection
REGULATOR
OUTPUT
J
Off
On
On
On
Off
= +160°C
WD
(1.6s
ENABLE is pulled to GND through an internal pulldown. HOLD is high
impedance (pulled up to OUT). Regulator output is disabled.
ENABLE is externally driven high turning the regulator output on.
HOLD is pulled up by OUT.
HOLD is externally pulled low while ENABLE remains high (latches
HOLD state).
ENABLE is driven low (or pulled low by an internal pulldown).
HOLD remains externally pulled low keeping the regulator output on.
HOLD is driven high (or pulled high by an internal pullup) while
ENABLE is low. Regulator output is shut off and ENABLE/
HOLD logic returns to the initial state.
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 output
voltage using the following equation:
where V
R2 is 50kΩ (maximum 100kΩ).
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:
where V
1.147V for L/T/Z/W versions.
Figure 2. RESETIN Threshold Selection
SET
TH
is 1.085V for the M/S/Y/V versions and
= 1.233V and the recommended value for
V
V
R3
R4
OUT
MON
V
RESETIN Threshold Selection
MON
COMMENT
= V
= V
RESETIN
SET
TH
MAX6769
MAX6770
(1 + R3 / R4)
(1 + R1 / R2)
GND
V
IN
IN
RESET