LTC2935IDC-3#TRMPBF Linear Technology, LTC2935IDC-3#TRMPBF Datasheet - Page 8

• Manufacturer Part Number: LTC2935IDC-3#TRMPBF
• Description: IC SUPERVISOR ULTRA LP 8-DFN
• Manufacturer: Linear Technology
• Type: Multi-Voltage Supervisorr

Specifications of LTC2935IDC-3#TRMPBF

• Number Of Voltages Monitored: 8
• Output: Open Drain or Open Collector
• Reset: Active Low
• Reset Timeout: 140 ms Minimum
• Voltage - Threshold: 8 Selectable Threshold Combinations
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-WFDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LTC2935IDC-3#TRMPBF; LTC2935IDC-3#TRMPBFTR

APPLICATIONS INFORMATION
LTC2935
Selecting Output Logic Style
The LTC2935 status outputs are available in two op-
tions: open-drain (LTC2935-1/LTC2935-3) or active
pull-up (LTC2935-2/LTC2935-4). The open-drain options
(LTC2935-1/LTC2935-3) allow the outputs to be pulled up
to a user defi ned voltage with a resistor. The open-drain
pull-up voltage may be greater than V
which is not always possible with inferior battery supervi-
sors, due to internal clamps. When the status outputs are
low, power is dissipated in the pull-up resistors. Recom-
mended resistor values lie in the range between 10k and
470k. Figure 1 demonstrates typical LTC2935-1/LTC2935-3
RST output behavior.
The active pull-up options (LTC2935-2/LTC2935-4) elimi-
nate the need for external pull-up resistors on the status
outputs. Integrated pull-up devices pull the outputs up to
V
V
Some applications require the RST and/or PFO outputs to
be valid with V
this requirement with the addition of an external resistor
from the output to ground. The resistor provides a path
for leakage currents, preventing the output from fl oating to
8
CC
CC
. Actively pulled up outputs may not be driven above
.
Figure 1. RST vs V
3.5
3.0
2.0
1.5
1.0
2.5
0.5
0
CC
0
LTC2935-1
S2 = GND
S1 = S0 = V
down to ground. Active pull-up handles
0.5
CC
1
1.5
V
CC
CC
with 10k Pull-Up
(V)
2
2.5
CC
(5.5V maximum),
3
2935 F01
3.5
undetermined voltages when connected to high impedance
(such as CMOS logic inputs). The resistor value should
be small enough to provide effective pull-down without
excessively loading the pull-up circuitry. A 100k resistor
from output to ground is satisfactory for most applications.
When the status outputs are high, power is dissipated in
the pull-down resistors. Figure 2 demonstrates typical
LTC2935-2/LTC2935-4 RST output behavior.
Manual Reset Input
When V
reset input (MR) is pulled low, the RST output is forced low.
RST remains low for 200ms after the manual reset input is
released and pulled high. The manual reset input is pulled
up internally through 900k to V
rents have the ability to pull down the manual reset input
below its logic threshold, a lower value pull-up resistor,
placed between V
Input MR is often pulled down through a pushbutton
switch requiring human contact. If extended ESD toler-
ance is required, series resistance between the switch and
the input is recommended. For most applications, a 10k
resistor provides suffi cient current limiting.
CC
3.0
2.0
3.5
2.5
1.5
1.0
0.5
is above its reset threshold, and the manual
0
0
LTC2935-2
S2 = GND
S1 = S0 = V
0.5
CC
Figure 2. RST vs V
and MR will fi x the problem.
CC
1
1.5
V
CC
(V)
2
CC
. If external leakage cur-
2.5
CC
3
2935 F02
3.5
2935fa