1
DEMO MANUAL DC101
SMART BATTERY CHARGER
LT1511 Level 2, Smart
Battery Charger Demo Board
with SMBus Interface
BLOCK DIAGRA A D BOARD PHOTO
U
W
DESCRIPTIO
U
The DC101 board is a standalone Smart Battery charger
that receives Charging Voltage(), Charging Current() and
AlarmWarning() commands from the Smart Battery via
the System Management Bus (SMBus) and sets charging
current and voltage accordingly. The charger continu-
ously monitors the built-in thermistor in the battery. The
thermistor information is used by the software to inhibit
charging at temperature extremes and to set charging
strategy for different battery chemistries.
, LTC and LT are registered trademarks of Linear Technology Corporation.
PERFOR A CE SU ARY
UWWW
PARAMETER CONDITIONS MIN TYP MAX UNIT
Input Voltage 16 24 27 V
Input Current Hardware Limited 2 A
Output Current Software Limited 0 2.5 A
Output Voltage Software Limited 4 20 V
Thermistor Resistance Ni-MH Battery 3 30 kΩ
Li-Ion Battery 0.5 1 1.5 kΩ
VOLTAGE PWM
CURRENT PWM
SHUTDOWN
DC OUT
GND
C SMBus
CLOCK (SCL)
D SMBus
DATA (SDA)
T THERMISTOR
BATTERY
CONNECTOR
+
–
5V
SMB µP
Q1
Q2
Q3
DC101 BD
LT
®
1511
CHARGER
FROM
WALL
CUBE
R10
SYSTEM CURRENT
5V
LT1129
+
–
26 14
15
2
11
PIC16C73
13
12
DC101 Smart Battery Charger
Component Side
2
DEMO MANUAL DC101
SMART BATTERY CHARGER
SCHE ATIC DIAGRA
WW
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
GND
SW
BOOST
GND
GND
UV
GND
OVP
CLP
CLN
COMP1
SENSE
GND
GND
V
CC1
V
CC2
V
CC3
PROG
V
C
UV
OUT
GND
COMP2
BAT
SPIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
MCLR
–
RA0/AN0
RA1/AN1
RA2/AN2
RA3/AN3
RA4
RA5/AN4
V
SS
OSC1
OSC2
RCO
CCP2
CCP1
SCL
RB7
RB6
RB5
RB4
RB3
RB2
RB1
RB0/INT
V
DD
V
SS
RC7
RC6
RC5
SDA
U2
LT1511
C11
10µF
25V
Q4
MMBT3904LT1
C4
1µF
25V
C3
33µF
25V
Q1
2N7002LT1
Q3
2N7002LT1
C10
10µF
25V
C5
1µF
25V
C8
0.1µF
C2
10µF
10V
C9
0.47µF
25V
D5
MBRS340T3
D3
MBRS340T3
L1
20µH
E1
E2
D4
BAS16LT1
R10
0.05Ω
1/2W
C9
0.1µF
24V
2A
J2
CENTER POST
IS POSITIVE
C16
100pF
50V
R20
200Ω
1/10W
1%
R2
301Ω
1/10W
1%
R18
1k
1/10W
1%
5V
BOLD LINES INDICATE HIGH CURRENT PATHS
R3
1k
1/10W
1%
R24
10k
5%
R15
21.5k
1/10W
0.1%
R23
22Ω
R8
0.033Ω
1/2W
5V
R19
200Ω
1/10W
1%
R14
330Ω
R13
143k
1/10W
0.1%
C7
0.015µF
25V
5%
C6
0.047µF
D6
BAS16LT1
C12
10µF
25V
J1
AMP-787441-1
SMART BATTERY
CONNECTOR
C18
10µF
10V
TP1 TP2 TP3 TP4 TP5
C20
10µF
25V
+
R12
100k
1/10W
0.1%
(+)
(+)
CLK
CLK
DATA
DATA
(T)
(T)
(–)
(–)
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
R11
510Ω
R16
3.32k
1/10W
1%
R17
1.05k
1/10W
1%
V
OUT
V
IN
2
DC IN
13
5V
4
GND
U3
LT1129IST-5
TAB
+
C17
0.1µF
Q2
2N7002LT1
UNLESS OTHERWISE SPECIFIED:
1. ALL RESISTANCES ARE IN OHMS, 1/10W, 5%
2. ALL CAPACITANCES ARE IN MICROFARADS, 50V, 10%
C14
33pF
SHUTDOWN
R4
3.32k
1%
U1
PIC16C73-20PS
CHARGER
ADJUSTMENT RANGE
PWM1: 3FFh = 22.4V
000h = 6V
PWM2:3FFh = 4.1A
000h = 0A
C15
33pF
Y1
4MHz
R7
3.32k
1%
5V
JPR1
RESET
C1
0.1µF
R26
10k
R5
330Ω
D1
RED
(SMB)
S1
5V
RESET
R6
330Ω
D2
GRN
(µP)
E3
DC OUT
E4
R1
3.32k
1/10W
1%
R9
100k
R21
22k
5%
5V
R25
22k
5%
5V
E5
DC101 SD
E6
E7
SMBCLK
SMBDATA
INT
R22
22k
5%
5V
Smart Battery Charger with SMBus Interface
3
DEMO MANUAL DC101
SMART BATTERY CHARGER
REFERENCE
DESIGNATOR QUANTITY PART NUMBER DESCRIPTION VENDOR TELEPHONE
C1, C8, C17, C19 4 12065C104KATMA 0.1µF 50V Chip Capacitor AVX (803) 946-0362
C2, C18 2 TAJB106M010 10µF 10V Tantalum Capacitor AVX (207) 282-5111
C3 1 12063G334ZAT2 0.33µF 25V Chip Capacitor AVX (803) 946-0362
C4, C5 2 12063G105ZATMA 1µF 25V Chip Capacitor AVX (803) 946-0362
C6 1 12065C473KAT 0.047µF 50V 10% Chip Capacitor AVX (803) 946-0362
C7 1 12063C153KAT2 0.015µF 25V 5% Chip Capacitor AVX (803) 946-0362
C9 1 12063G474ZAT2 0.47µF 25V Chip Capacitor AVX (803) 946-0362
C10, C11, C12, C20 4 THCS50E1E106Z 10µF 25V Ceramic Capacitor Marcon (847) 696-2000 x374
C14, C15 2 1206A330KAT2 33pF 50V Chip Capacitor AVX (803) 946-0362
C16 1 VJ1206A101KXA 100pF 50V Chip Capacitor Vitramon (203) 268-6261
D1 1 SF1-BR Red LED Data Display Product (800) 421-6815
D2 1 SF1-G Green LED Data Display Product (800) 421-6815
D3, D5 2 MBRS340T3 Diode Motorola (602) 244-3576
D4, D6 2 BAS16LT1 Diode Motorola (602) 244-3576
J1 1 AMP-787441-1 Connector AMP (717) 780-4409
J2 1 CUI-PJ-002A Connector Cui-Stack (503) 643-4899
JPR1 1 3801S-12-G1 12-Pin Header Jumper Comm Con Conn. (818) 301-4200
L1 1 CTX20-4 20µH Inductor Coiltronics (407) 241-7876
Q1,Q2, Q3 3 2N7002LT N-Channel MOSFET Motorola (602) 244-3576
Q4 1 MMBT3904LT1 NPN Transistor Motorola (602) 244-4342
R1, R4, R16 3 CR32-3321F-T 3.32k 1/8W 1% Resistor AVX (803) 946-0524
R2 1 CR32-3010F-T 301Ω 1/8W 1% Resistor AVX (803) 946-0524
R3, R18 2 CR32-1001F-T 1k 1/8W 1% Resistor AVX (803) 946-0524
PACKAGE DIAGRA
W
1
2
3
4
5
6
7
8
9
10
11
12
TOP VIEW
SW PACKAGE
24-LEAD PLASTIC SO WIDE
24
23
22
21
20
19
18
17
16
15
14
13
GND
SW
BOOST
GND
GND
UV
GND
OVP
CLP
CLN
COMP1
SENSE
GND
GND
V
CC1
V
CC2
V
CC3
PROG
V
C
UV
OUT
GND
COMP2
BAT
SPIN
LT1511CSW
PARTS LIST
4
DEMO MANUAL DC101
SMART BATTERY CHARGER
REFERENCE
DESIGNATOR QUANTITY PART NUMBER DESCRIPTION VENDOR TELEPHONE
R5, R6, R14 3 CR32-331J-T 330Ω 1/8W 5% Resistor AVX (803) 946-0524
R7 1 BCR1/8-3322F-T 33.2k 1/8W 1% Resistor Beckman (714) 447-2345
R8 1 LR2010-01-R033-J 0.033Ω 1/2W 5% Resistor IRC (512) 992-7900
R9 1 CR32-104J-T 100k 1/8W 5% Resistor AVX (803) 946-0524
R10 1 LR2010-01-R050-J 0.05Ω 1/2W 5% Resistor IRC (512) 992-7900
R11 1 CR32-511J-T 510Ω 1/8W 5% Resistor AVX (803) 946-0524
R12 1 W1206R-03-1003-B 100k 1/8W 0.1% Resistor IRC (512) 992-7900
R13 1 W1206R-03-1433-B 143k 1/10W 0.1% Resistor IRC (512) 992-7900
R15 1 W1206R-03-2152-B 21.5k 1/10W 0.1% Resistor IRC (512) 992-7900
R17 1 CR32-1051F-T 1.05k 1/8W 1% Resistor AVX (803) 946-0524
R19, R20 2 CR32-2000F-T 200Ω 1/8W 1% Resistor AVX (803) 946-0524
R21, R22, R25 3 CR32-223J-T 22k 1/10W 5% Resistor AVX (803) 946-0524
R23 1 CR32-220J-T 22Ω 1/10W 5% Resistor AVX (803) 946-0524
R24, R26 2 CR1206-103J 10k 1/8W 5% Resistor Dale (605) 665-9301
S1 1 MJTP1230 PB Switch MORS-ASC (617) 246-1007
TP1 to TP5, E1 to E7 12 1502-2 Turret Testpoint Keystone (718) 956-8900
U1 1 PIC16C73-20SP Microcontroller IC Microchip (602) 786-7200
U2 1 LT1511 Battery Charger IC LTC (408) 432-1900
U3 1 LT1129IST-5 Voltage Regulator IC LTC (408) 432-1900
XU1 1 7167-14-G2 Sockets IC Comm Con (818) 301-4200
Y1 1 MA-505-4.00M-C2 4MHz Crystal Epson (USA) (310) 787-6300
OPERATIO
U
Input Voltage: The nominal input voltage of the board is
24V DC. The input voltage must be higher than the battery
voltage by a minimum of 3V. The minimum input voltage
is 16V, limited by the undervoltage lockout circuit in the
LT1511 and set by resistors R16, R17 and R18. The
highest input voltage is 27.4V, limited by the maximum
input voltage of the LT1511. The input is protected against
reverse polarity up to 30V.
Input Current: The sum of the system current and the
charger input current is limited by the LT1511 to 2A. When
both the system current and the charger input current
requirements are high, the charger reduces the charging
current to meet the 2A current limit.
Red LED: A red LED indicates SMBus activity. It lights up
for about 1 second when the charger recognizes its own
address (12 hex) on the SMBus.
Green LED: A flashing green LED indicates microproces-
sor activity and charger status. Fast blinking (approxi-
mately 8Hz) indicates normal microprocessor activity and
either trickle charge or shutdown charger status. After
valid voltage and current data have been received, the
blinking speed of the LED slows down to about 2Hz,
indicating normal charging.
PARTS LIST
5
DEMO MANUAL DC101
SMART BATTERY CHARGER
OPERATIO
U
Battery Removal, Thermistor Measurements: The
charger periodically checks the thermistor in the battery
through the T-terminal. When the thermistor is out of
normal operating temperature range, the charger switches
to trickle charge mode and increases the flashing fre-
quency of the green LED to indicate an abnormal charg-
ing condition. When the resistance of the thermistor is in
the 500Ω < R
TH
< 1.5k range, the charger assumes a Li-
Ion battery is at the output. Instead of trickle charging the
battery it shuts down the charger until a valid voltage and
current request arrives from the battery. An open ther-
mistor forces the charger into trickle charge mode and
the charger disregards data on the SMBus.
System Management Bus (SMBus)
When charge in the Smart Battery (SB) drops below 85%
of the nominal capacity, it initiates communication over
the SMBus every 64 seconds. After sending a START
sequence, the battery addresses the Smart Battery charger
and waits for an acknowledgment (ACK) from it. If the
charger fails to acknowledge the word, the battery termi-
nates further communication by placing a STOP sequence
onto the SMBus. If the charger acknowledges (ACK) the
reception of the first word, the battery continues the
communication sequence and sends six more words to
the charger. The complete current and voltage request
communication sequence is as follows:
START
address (12 hex)
Charging Current() command code (14 hex),
current_LSB
current_MSB,
address (12 hex)
Charging Voltage() command code (15 hex)
voltage_LSB
voltage_MSB
STOP
The idealized SMBus waveforms shown in Figure 1 illus-
trate SMBus communication between the battery and the
charger. The first seven bits after the START sequence are
the battery address. The R/W bit tells the charger that the
battery is attempting to write to the charger. During the
acknowledge period (ACK), the charger becomes active
and pulls the data line (SDA) low, indicating reception of
a data word. When reception of the data word is not
acknowledged by the charger, the battery terminates the
communication by sending a STOP sequence to the bus.
The clock pulses for the communication are always gen-
erated by the battery (BUS MASTER).
“C” Source Code
The latest version of “C” language source code, header
file, code file and hex dump file is provided on a 3.5" disk.
SCLK
SDA
START
1 2 0 = WRITE
1 = 1ST NIBBLE
2 = 2ND NIBBLE (TRUNCATED)
THIS EXAMPLE = 12(H)
DC101 F01
0001001R/WACK
Figure 1. SMBus Waveforms Indicating Battery Address
6
DEMO MANUAL DC101
SMART BATTERY CHARGER
OPERATIO
U
12C DATA RECEIVED
THERMISTOR OPEN
A/D COUNTER = 0
ALARM WARNING
ON STACK
CHARGING CURRENT
ON STACK
CHARGING VOLTAGE
ON STACK
ERROR FLAG
SET SLOW BLINKING
INIT VARIABLES START
Y
THERMISTOR TOO HOT
THERMISTOR
IN RANGE
THERMISTOR
TOO COLD
Li-Ion
Y
INTERRUPT
RETURN FROM
INTERRUPT
TURN RED LED ON
FOR 2 SEC
RESET 12C POINTER
DISABLE INTERRUPTS
PUT 12C DATA ON THE
12C STACK INCREMENT
POINTER
ENABLE INTERRUPTS
Y
SET ERROR FLAG
SHUT DOWN CHARGER
ERASE COMMAND
Y
Y
Y
Y
Y
Y
LOAD IPWM
ERASE COMMAND
ENABLE CHARGER
ERASE ERROR FLAG
Y
LOAD VPWM
ERASE COMMAND
ENABLE CHARGER
ERASE ERROR FLAG
SET TRICKLE CHARGE
SET ERROR FLAG
IF NO Li-Ion FLAG:
INIT Li-Ion MODE
ERASE ERROR FLAG
IF Li-Ion FLAG SET:
ERASE Li-Ion FLAG
ERASE ERROR FLAG
INIT Ni-MH MODE
Y
SET FAST BLINKING
MEASURE THERMISTOR
THERMISTOR
SHORTED
Figure 2. Software Flowchart
7
DEMO MANUAL DC101
SMART BATTERY CHARGER
PCB LAYOUT A D FIL
UW
Component Side Silkscreen
Component Side
Component Side Solder Mask
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 circuits as described herein will not infringe on existing patent rights.
8
DEMO MANUAL DC101
SMART BATTERY CHARGER
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX
: (408) 434-0507
●
TELEX
: 499-3977
LINEAR TECHNOLOGY CORPORATION 1996
LT/GP 0796 500 • PRINTED IN USA
PCB LAYOUT A D FIL
UW
Solder Side
Solder Side Solder Mask
PC FAB DRAWI G
U
A
A
0.150"
0.150"
0.150"
A
DC101 FD
F
A
B
D
D
NOTES
1.MATERIAL: 2 LAYERS, 0.062" THICK.
FR-4 GLASS EPOXY 2 OZ COPPER CLAD
2.ALL HOLES SHALL BE PLATED THROUGH
3.PLATE THROUGH HOLES WITH COPPER
0.0014 MIN THICKNESS. ALL HOLE SIZES
IN HOLE TABLE ARE AFTER PLATING
4.SILKSCREEN: WITH WHITE EPOXY
NONCONDUCTIVE INK
5.FINISH: SMOBC
6.SOLDER MASK: USE FILM PROVIDED, GREEN
D
GG
G
B
E
E
E
H
H
H
H
H
H
H
H
H
H
H
H
C
SYMBOL
A
B
C
D
E
F
G
H
DIAMETER
125
120
100
94
40
39
37
18
TOTAL HOLES
NUMBER
OF HOLES
4
2
1
12
14
4
40
55
132
0.219"
0.150"
2.744"
3.900"
3.019"
/