23

LTC1325

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.

However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-

tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

LABEL MNEMONIC OPERAND

COMMENTS

LDAA

#$51

Write control byte to the SPCR

STAA

$1028

LDAA

#$39

Setup Port D DDRD

STAA

$1009

Port D Bit 0 is CS

LDX

#$1000

Load port base ADDR

CSLOW BCLR

$08,X,#$01

Take CS low

LDAA

#$02

Send Byte #1 (MSB) with

STAA

$102A

START bit

LOOP1 TST

$1029

Check for SPI transfer

BPL

LOOP1

complete bit

LDAA

#$24

Send Byte 2

STAA

$102A

LOOP2 TST

$1029

Check for SPI transfer

BPL

LOOP2

complete bit

LDAA

#$03

Send Byte 3

STAA

$102A

LOOP3 TST

$1029

Check for SPI transfer

BPL

LOOP3

complete bit

LDAA

#$C0

Send Byte 4

STAA

$102A

LABEL MNEMONIC OPERAND

COMMENTS

LOOP4 TST

$1029

Check for SPI transfer

BPL

LOOP4

complete bit

LDAA

$102A

Get A/D high byte

ANDA

#$03

Mask off unwanted bits

STAA

HIDATA

Store in user memory

LDAA

#$00

Send dummy Byte #1

STAA

$102A

LOOP5 TST

$1029

Check for SPI transfer

BPL

LOOP5

complete bit

LDAA

$102A

Get A/D low byte

STAA

LODATA

Store in user memory

LDAA

#$00

Send dummy Byte #2

STAA

$102A

LOOP6 TST

$1029

Check for SPI transfer

BPL

LOOP6

complete bit

LDAA

$102A

Get STATUS byte

STAA

STATUS

Store in user memory

BSET

$08,X,#$01

Raise CS high

BRA

CSLOW

Loop for continuous readings

Wide Voltage Battery Charger

NOTE 2: REGULATOR. OMIT THIS BLOCK AND SHORT

NOTE 3: LEVEL SHIFTER. OMIT THIS BLOCK AND SHORT

1325 TA02

NOTE 7: OPTIONAL DIODE TO PREVENT BATTERY

DRAIN WHEN THE CHARGING SUPPLY IS POWERED

DOWN (SEE SECTION 2, HARDWARE DESIGN

PROCEDURE).

P1

IRF9Z30

25V

R8

100

Ω

1

µF

PGATE

DIS

SENSE

FILTER

REG

CS

CLK

LTF

MCV

HTF

GND

R1

R11

220

Ω

1/2W

R2

R3

R4

+

4.7

µF

MPU

(e.g. 8051)

p1.4

p1.3

p1.2

+

C1

1

µF

C2

0.1

µF

R13

R6

N1

IRF830

C3

500pF

THERM 2

R5

LTC1325

THERM 1

R7

L1

62

µH

R9

NOTE 5

NOTE 3

NOTE 1

NOTE 1

NOTE 2

R10

D1

1N5818

D3

1N4740A

D4

1N4744A

15V

R12

100k

NOTE 1

NOTE 4

D2

1N4744A

15V

NOTE 6

+

C4

22

µF

R14

100

Ω

MBR320

NOTE 7

C5

0.1

µF

NOTE 5: EXTERNAL BATTERY DIVIDER. NEEDED WHEN