ISL78610 Datasheet, PDF (79/98 Pages) Intersil Corporation – Multi-Cell Li-Ion Battery Manager

ISL78610
Worked Examples
The following worked examples are provided to assist with the
setup and calculations associated with various functions.
Voltage Reference Check Calculation
TABLE 48. EXAMPLE REGISTER DATA
R/W PAGE ADDRESS
PARAMETER
VALUE
(HEX) DECIMAL
0 001 010000 IC Temperature
14’h2425 9253
0 001 010101 Reference Voltage 14’h20A7 8359
0 010 111000 Coefficient C
14’h00A4 164
0 010 111001 Coefficient B
14’h3FCD -51
0 010 111010 Coefficient A
9’h006
6
Coefficients A, B and C are two’s compliment numbers. B and C
have a range +8191 to -8192. A has a range +255 to -256.
Coefficient B above is a negative number (Hex value > 1FFF).
The value for B is 14’h3FCD - 14h3FFF- 1 or (16333₁₀ –
16383₁₀ - 1) = -51.
Coefficient A occupies the upper 9 bits of register 6’b111010
(6'h3A). One way to extract the coefficient data from this register
is to divide the complete register value by 32 and rounding the
result down to the nearest integer. With 9'h006 in the upper 9
bits, and assuming the lower 5 bits are 0, the complete register
value will be 14'h0C0 = 192 decimal. Divide this by 32 to
obtain 6.
Coefficients A, B and C are used with the IC temperature reading
to calibrate the Reference Voltage reading. The calibration is
applied by subtracting an adjustment of the form from the
reference voltage reading:
Adjustment = ₂----₅---₆-----_-^A----₈---₁---₉----₂--  dT² + ₈----₁-^B--₉---₂--  dT + C
(EQ. 5)
An example calculation using the data of Table 48 is given in
Equation 6.
dT = ⁹----²---⁵---³-----₂^–-----9---¹---⁸----⁰-- = 36.5
(EQ. 6)
Where 9180 is the internal temperature monitor reading at +25°C
(see the ““MEASUREMENT SPECIFICATIONS” on page 8).
Adjustment
=
2^----5^---6^-----^--6---8^---1^---9^----2^{--  36.52 –} 8^{----51---19----}2^{-  36.5 + 164 =}
163.8
(EQ. 7)
Corrected V_REF = 8359 – 163.8 = 8195.2
V_REF value = ⁸-₁---¹-₆--⁹-₃---⁵⁸---^.-₄-²-  5 = 2.5010
(EQ. 8)
(EQ. 9)
Cell Balancing – Manual Mode
Refer to “Manual Balance Mode” on page 46.
EXAMPLE: ACTIVATE BALANCING ON CELLS 1, 5, 7
AND 11
Step 1. Write Balance Setup register: Set Manual Balance mode,
Balance Status pointer, and turn off balance.
BMD = 01 (Manual Balance mode)
BWT = XXX
BSP = 0000 (Balance Status Pointer location 0)
BEN = 0 (Balancing disabled)
Note: Blue text indicates a register change.
TABLE 49. BALANCE SETUP REGISTER
R/W PAGE ADDRESS
DATA
1 010
010011
XX XX00 000X XX01
X = don’t care
Step 2. Write Balance Status register: Set bits 0, 4, 6 and 10
BAL12:1 = 0100 0101 0001
TABLE 50. BALANCE STATUS REGISTER
R/W PAGE ADDRESS
DATA
1
010 010100
XX 0100 0101 0001
Step 3. Enable balancing using Balance Enable command
TABLE 51. BALANCE ENABLE COMMAND
R/W PAGE ADDRESS
DATA
0
011 010000
00 0000
Or enable balancing by setting BEN directly in the Balance Setup
register:
BEN = 1
TABLE 52. BALANCE SETUP REGISTER
R/W PAGE ADDRESS
DATA
1
010
010011
XX XX1X XXXX XXXX
The balance FETs attached to cells 1, 5, 7 and 11 turn on.
Turn balancing off by resetting BEN or by sending the Balance
Inhibit command (Page 3, address 6’h11).
Submit Document Feedback ₇₉
FN8830.1
June 16, 2016