LTC2906/LTC2907
6
29067f
UU
U
PI FU CTIO S
V
CC
(Pin 1/Pin 4): Optional Power Supply Pin. V
CC
powers
and maintains the correct operation of the RST and RST
pins in the complete absence of V1. If V1 is present, the
greater of V
CC
or V1 (V
MAX
) powers the internal circuitry
and the reset outputs. Bypass this pin to ground with a
0.1µF (or greater) capacitor. Tie to V1 when no optional
power is available.
RST (Pin 2/Pin 3): (LTC2906 Only) Reset Logic Output.
When all voltage inputs are above the reset threshold for
at least the programmed delay time, this pin pulls low. This
pin has a weak pull up to V
MAX
and may be pulled above
V
MAX
using an external pull-up.
TMR (Pin 2/Pin 3): (LTC2907 Only) Reset Delay Time
Programming Pin. Attach an external capacitor (C
TMR
) to
GND to set a reset delay time of 9ms/nF. Leaving the pin
open generates a minimum delay of approximately 200µs.
A 22nF capacitor will generate a 200ms reset delay time.
RST (Pin 3/Pin 2): Inverted Reset Logic Output. Pulls low
when either V1 or V
ADJ
is below the reset threshold and
holds low for programmed delay time after all voltage
inputs are above threshold. This pin has a weak pull up to
V
MAX
and may be pulled above V
MAX
using an external
pull-up.
GND (Pin 4/Pin 1 and Pin 9): Ground.
TOL (Pin 5/Pin 8): Three-State Input for Supply Tolerance
Selection (5%, 7.5% or 10%). Refer to Applications Infor-
mation for tolerance selection chart (Table 3).
S1 (Pin 6/Pin 7): The Voltage Threshold Select Three-
State Input. Connect to V1, GND or leave unconnected in
open state to select one of three possible input threshold
levels (refer to Table 1).
V
ADJ
(Pin 7/Pin 6): Adjustable Voltage Input. Bypass this
pin to ground with a 0.1µF (or greater) capacitor in a noisy
environment.
V1 (Pin 8/Pin 1): Voltage Input 1. Select from 5V, 3.3V or
2.5V. Refer to Table 1 for details. The greater of (V1, V
CC
)
is also the internal V
CC
(V
MAX
). Bypass this pin to ground
with a 0.1µF (or greater) capacitor.
(TS8 Package/DDB8 Package)
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TEMPERATURE (°C)
I
S1
, I
TOL
(µA)
–20
–19
–18
–17
–16
–15
–14
–13
–12
–11
–10
29067 G22
–50 100
25
75
–25
0
50
S1 = TOL = GND
V1 = 3.3V
I
S1
, I
TOL
vs Temperature
Specifications are at T
A
= 25°C unless otherwise noted.
