X3100 datasheet(21/40 Pages) RENESAS

21 / 40 page

X3100, X3101

FN8110 Rev 1.00

Page 21 of 40

January 3, 2008

MONITOR MODE

Analog Multiplexer Selection

The X3100 and X3101 can be used to externally monitor

individual battery cell voltages, and battery current. Each

quantity can be monitored at the analog output pin (AO),

and is selected using the analog select (AS0 - AS2) pins

(Table 25). Also, see Figure 7.

Current Monitor Function

The voltages monitored at pins VCS1 and VCS2 can be

used to calculate current flowing through the battery ter-

minals, using an off-board microcontroller with an A/D.

Since the value of the sense resistor (RSENSE) is small

(typically in the order of tens of m

and since the reso-

lution of various A/D converters may vary, the voltage

across RSENSE (VCS1 and VCS2) is amplified internally

with a gain of between 10 and 160, and output to pin AO

(Figure 7).

Figure 7. X3100/X3101 Monitor Circuit

[3]

— The device detects the load resistance has risen above ROCR.

— Voltages P+ and VCS21 return to their normal levels.

— The test current from pin OVP/LMON is stopped (ILMON = 0µA)

— The device has now returned from the load monitor state

— The internal over-current release time timer begins counting down.

— Device is still in over-current protection mode.

(3,4)

The internal over-current release timer continues counting for TOCR seconds.

[4]

— The internal over-current release timer times out, and VCS21 is still below VOC.

— The device returns from over-current protection mode, and is now in normal operation mode.

— The discharge FET is automatically switched ON (UVP/OCP = Vss)—unless the status of UVPC has been

changed in the control register during the over-current protection mode.

— The status of the charge FET remains unaffected.

— Discharge of the battery cells is once again possible.

Table 24. Over-Current Protection Mode—Event Diagram Description (Continued)

Event

Event Description

Table 25. AO Selection Map

AS2 AS1 AS0

AO output

VSS(1)

VCELL1 - VCELL2 (VCELL12)

VCELL2 - VCELL3 (VCELL23)

VCELL3 - VCELL4 (VCELL34)

VCELL4 - Vss (VCELL4)

VCS1 - VCS2 (VCS12)(2)

VCS2 - VCS1 (VCS21)(2)

VSS

Notes: (1) This is the normal state of the X3100 or X3101. While

in this state Over-charge and Over-discharge Protec-

tion conditions are periodically monitored (See “Peri-

odic Protection Monitoring” on page 13.)

(2) VCS1, VCS2 are read at AO with respect to a DC bias

voltage of 2.5V (See section “Current Monitor Func-

tion” on page 21).

Over-Current

Protection

VCS1

VCS2

CSG1 CSG0

Config

AS0

AS1

AS2

SPI

I/F

SCL

RSENSE

Gain

Setting

Cross-Bar

Switch

X3100/X3101

OP1

Voltage

Level

Shifters

Cell 1 Voltage

Cell 2 Voltage

Cell 3 Voltage

Cell 4 Voltage

2.5V

P-

X3100 Datasheet(PDF) 21 Page - Renesas Technology Corp

X3100 Datasheet(HTML) 21 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

Datasheet Download

Link URL