MAX6775 MAXIM [Maxim Integrated Products], MAX6775 Datasheet - Page 8

• Manufacturer Part Number: MAX6775
• Description: Low-Power, 1%-Accurate Battery Monitors in uDFN and SC70 Packages
• Manufacturer: MAXIM [Maxim Integrated Products]

Setting the hysteresis externally requires calculating
three resistor values, as indicated in Figure 3. First cal-
culate R
and R
(as in the above example). Where R
R
I
Then, determine R
Low-Power, 1%-Accurate Battery
Monitors in µDFN and SC70 Packages
8
TOTAL
HYST
MAX6775XK_+T
MAX6775LT_+T
MAX6776XK_+T
MAX6776LT_+T
MAX6777XK+T
MAX6777LT+T
MAX6778XK+T
MAX6778LT+T
MAX6779LT_+T
MAX6780LT_+T
MAX6781LT_+T
_______________________________________________________________________________________
L0
, at the trip voltage using:
, determine the total resistor-divider current,
H
using:
PART
using:
R
I
R
L
TOTAL
H
0
R
HYST
HYST
Hysteresis Resistive Divider
=
=
−
e
=
using:
A
V
=
LBIR
Calculating an External
V
R
LBIR
x V
H
I
I
V
TOTAL
L
V
LBO OUTPUT
HYST
BATT
+
BATT
−
x R
Single
Single
Single
Single
Single
Single
Single
Single
V
R
Dual
Dual
Dual
BATT
L
0
H
L0
equals R
OUTPUT TYPE
L
Open-Drain
Open-Drain
Open-Drain
Open-Drain
Open-Drain
+
Push-Pull
Push-Pull
Push-Pull
Push-Pull
Push-Pull
Mixed
where V
Finally, determine R
For monitoring higher voltages, supply power to BATT
that is within the specified supply range, and power the
input resistive divider from the high voltage to be moni-
tored. Do not exceed the Absolute Maximum Ratings.
If monitoring voltages in a noisy environment, add a
bypass capacitor of 0.1µF from BATT to GND as close
as possible to the device. For systems with large tran-
sients, additional capacitance may be required. A small
capacitor (<1nF) from LBI_ to GND may provide addi-
tional noise immunity.
HYST
Monitoring a Battery Voltage Higher
is the required hysteresis voltage.
Adding External Capacitance to
HYSTERESIS
Adjustable
Adjustable
Adjustable
Adjustable
Reduce Noise and Transients
Fixed
Fixed
Fixed
Fixed
Fixed
Fixed
Fixed
R
L
L
using:
Than the Allowable V
= R
L0
- R
Selector Guide
HYST
PIN-PACKAGE
6 µDFN-6
6 µDFN-6
6 µDFN-6
6 µDFN-6
6 µDFN-6
6 µDFN-6
6 µDFN-6
5 SC70-5
5 SC70-5
5 SC70-5
5 SC70-5
BATT