X3100V28T1 Intersil, X3100V28T1 Datasheet - Page 22

• Manufacturer Part Number: X3100V28T1
• Description: IC PROTECT/MONITOR 4CELL 28TSSOP
• Manufacturer: Intersil

Specifications of X3100V28T1

• Function: Battery Monitor
• Battery Type: Lithium-Ion (Li-Ion)
• Voltage - Supply: 6 V ~ 24 V
• Operating Temperature: -20°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-TSSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The internal gain of the X3100 or X3101 current sense
voltage amplifier can be selected by using the WCNTR
Instruction to set bits CSG1 and CSG0 in the control
register (Table 14). The CSG1 and CSG0 bits select
one of four input resistors to Op Amp OP1. The feed-
back resistors remain constant. This ratio of input to
feedback resistors determines the gain. Putting exter-
nal resistors in series with the inputs reduces the gain of
the amplifier.
VCS
bias voltage of 2.5V. Therefore, the voltage range of
VCS
tion of current flow (i.e. battery cells are in Charge or
Discharge—Table 21).
Table 26. AO Voltage Range for VCS
By calculating the difference of VCS
offset voltage of the internal op-amp circuitry is can-
celled. This allows for the accurate calculation of cur-
rent flow into and out of the battery cells.
Pack current is calculated using the following formula:
VOLTAGE REGULATOR
The X3100 and X3101 are able to supply peripheral
devices with a regulated 5VDC±0.5% output at pin
RGO. The voltage regulator should be configured
externally as shown in Figure 8.
The non-inverting input of OP1 is fed with a high preci-
sion 5VDC supply. The voltage at the output of the
voltage regulator (V
ence via the inverting input of OP1. The output of OP1
in turn drives the regulator pnp transistor (Q1). The
negative feedback at the regulator output maintains
the voltage at 5VDC±0.5% (including ripple) despite
changes in load, and differences in regulator transistors.
When power is applied to pin VCC of the X3100 or
X3101, V
time of T
“tuned” to attain a final value of 5VDC±0.5% (Figure ).
VCS
VCS
VCS
VCS
Pack Current
AO
1
12
and VCS
and VCS
21
21
12
12
RGO
OC
+2ms. During this time period, V
Cell State
is regulated to 5VDC±10% for a nominal
Discharge
Discharge
Charge
Charge
2
=
21
are read at AO with respect to a DC
--------------------------------------------------------------------------------------------------------- -
2 ( ) gain setting
changes depending upon the direc-
RGO
(
) is compared to this 5V refer-
22
(
VCS
)(current sense resistor)
AO Voltage Range
12
2.5V
2.5V
0V
0V
–
VCS
≤
≤
12
≤
≤
AO
AO
21
12
AO
AO
and VCS
)
and VCS
≤
≤
≤
≤
2.5V
2.5V
5.0V
5.0V
RGO
21
X3100, X3101
21
the
is
The maximum current that can flow from the voltage
regulator (I
resistor (R
When the voltage across VCC and RGP reaches a
nominal 2.5V (i.e. the threshold voltage for the FET), Q2
switches ON, shorting VCC to the base of Q1. Since
the base voltage of Q1 is now higher than the emitter
voltage, Q1 switches OFF, and hence the supply current
goes to zero.
Typical values for R
27. In order to protect the voltage regulator circuitry
from damage in case of a short-circuit, R
should always be used.
Table 27. Typical Values for R
When choosing the value of R
of the PNP transistor used should also be taken into
consideration. The transistor should have a gain of at
least 100 to support an output current of 250mA.
Figure 8. Voltage Regulator Operation
4KBIT EEPROM MEMORY
The X3100 and X3101 contain a CMOS 4k-bit serial
EEPROM, internally organized as 512 x 8 bits. This
memory is accessible via the SPI port, and features
the IDLock function.
R
10Ω
25Ω
50Ω
Precision
Reference
Tuning
To Internal Voltage
Regulating Circuitry
5VDC
Voltage
LMT
X3100/X3101
LMT
LMT
Voltage Regulator Current Limit (I
) connected between RGP and VCC.
) is controlled by the current limiting
LMT
+
_
250mA ± 50% (Typical)
100mA ± 50% (Typical)
OP1
50mA ± 50% (Typical)
and I
Q2
LMT
LMT
RGC
RGO
VCC
RGP
LMT
, the drive limitations
are shown in Table
and I
LMT
Un-Regulated
Regulated
5VDC Output
Q1
LMT
0.1
µF
R
January 3, 2008
I
Voltage
Input
LMT
LMT
≥ 10Ω
FN8110.1
V
LMT
RGO
)