PS810
Li Ion Single Cell Fuel Gauge
H
ardware Features
• Highly accurate fuel gauge for single cell Li Ion
applications
• Algorithms are implemented using an embedded
PIC18 low-power microcontroller with 16-bit
instruction set
• Reports current, voltage and temperature utilizing a
programmable 8 to15-bit + sign, sigma-delta ADC
• Host communication accomplished through an
industry standard SMBus interface or an
alternative single pin serial interface
• I/O pins are available to provide functions such as
digital GPIO, coin cell voltage measurement and
thermistor input
• Integrated temperature sensor and regulator
minimize external components
• Embedded fuel gauge algorithms and application
specific parameters are stored in a 4K x 16 Flash
memory
• 512 bytes of RAM are available for temporary
storage of battery parameters
Pin Description
16-pin QFN (4 mm x 4 mm)
SDA/SPS
IO6
SCL/IO0
16 15 14 13
NTC/IO2
V
COIN
/IO3
V
FILTER
MCLR
1
2
3
4
5 6
VC1
N/C
7 8
N/C
R
OSC
12
IO5
IO4
GND
SR
11
10
9
14-pin TSSOP
SCL/IO0
IO1
NTC/IO2
V
COIN
/IO3
V
FILTER
MCLR
VC1
1
2
14
13
SDA/SPS
IO6
IO5
IO4
GND
SR
R
OSC
PS810
3
4
5
6
7
IO1
PS810
12
11
10
9
8
Software Features
• Provides battery status, such as average time to empty,
relative State-Of-Charge and battery State-Of-Health
• In-system offset calibration compensates for
offset error in current measurement
Package Features
• 16-pin QFN package or 14-pin TSSOP package
• -20°C to +85°C operating temperature range
1.0
PRODUCT OVERVIEW
To provide precise measurements of current, voltage and
temperature, the PS810 integrates a highly accurate
15-bit + sign, sigma-delta A/D converter. Based upon
operating conditions, this programmable converter can be
configured to measure specific battery parameters with a
resolution of 8 to 15 bits + sign. Precision measurements
combined with advanced algorithms provide accurate
indications of capacity, run time, State-Of-Health and
safety and charge/discharge conditions.
The ability to operate directly from a single Li Ion or Li
Polymer cell minimizes the need for external compo-
nents, such as a voltage regulator and voltage divider.
To further limit external circuitry and enhance accuracy,
the PS810 provides an integrated temperature sensor
and oscillator.
The PS810 is a fuel gauge for one-cell Li Ion or Li Poly-
mer applications. The device provides the host and the
system user with critical battery information, such as
voltage, current, temperature, run time, State-Of-Charge
and State-Of-Health. This information is available
through an industry standard SMBus or an alternative
Single Pin Serial interface. Advanced fuel gauge
algorithms are stored in on-board Flash memory and
executed by the industry recognized PIC18 micro-
controller. These algorithms include compensation
factors which optimize the performance of the battery for
a specific application and operating environment.
Compensation is included for the effects of temperature,
discharge rate, charge rate and battery aging.
©
2006 Microchip Technology Inc.
DS21904C-page 1
PS810
TABLE 1-1:
Pin# Pin Name
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
NTC/IO2
V
COIN
/IO3
V
FILTER
MCLR
VC1
N/C
N/C
R
OSC
SR
GND
IO4
IO5
IO6
SDA/SPS
SCL/IO0
IO1
PS810 QFN PIN SUMMARY
Description
External NTC input or GPIO
Coin cell monitor input or GPIO
Power supply filter cap
Master Clear
Cell voltage input
No connect
No connect
Oscillator bias resistor
Sense resistor input
Power supply ground
General purpose IO
General purpose IO
General purpose IO
SMBus data/one-wire serial line
SMBus clock or GPIO0
General purpose IO
TABLE 1-2:
Pin#
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Pin Name
SCL/IO0
IO1
NTC/IO2
V
COIN
/IO3
V
FILTER
MCLR
VC1
R
OSC
SR
GND
IO4
IO5
IO6
SDA/SPS
PS810 TSSOP PIN SUMMARY
Description
SMBus clock or GPIO
General purpose IO
External NTC input or GPIO
Coin cell monitor input or GPIO
Power supply filter cap
Master Clear
Cell voltage input
Oscillator bias resistor
Sense resistor input
Power supply ground
General purpose IO
General purpose IO
General purpose IO
SMBus data/one-wire serial line
FIGURE 1-1:
PS810 INTERNAL BLOCK DIAGRAM
Digital Section
Analog Section
V
FILTER
Voltage
Voltage
Reference and
Reference and
Temp Sensor
Temp Sensor
Voltage
Voltage
Regulator
Regulator
4K x
x
16 Flash
4K 16 Flash
512-byte RAM/
512-byte RAM/
Registers
Registers
VC1
SDA/SPS
PIC18F
PIC18F
Microcontroller
Microcontroller
Comm
Comm
Interface
Interface
Control and Status
Control and Status
Run
Run
Oscillator
Oscillator
IO0
IO1
IO2
Input/Output
Input/Output
Sleep
Sleep
Oscillator
Oscillator
15-bit +
+
sign
15-bit sign
Sigma-Delta
Sigma-Delta
Integrating
Integrating
A/D Converter
A/D Converter
Analog
Analog
Input Mux
Input Mux
SR
NTC
V
COIN
SCL
R
OSC
IO3 IO4 IO5 IO6
MCLR
GND
DS21904C-page 2
©
2006 Microchip Technology Inc.
1.1
Schematic
FIGURE 1-2:
DO
CELL CONNECTIONS
6
4
5
NC
NC
PS810Q
U1
QFN PACKAGE
4
5
R9
GROUND PLANE
CONNECTION
0.020
6
7
7
V1
C10
1.0 nF
C5
100 nF
232K
VC1
R
OSC
V
SS
VR
CO
8
1
©
2006 Microchip Technology Inc.
15
SCL/IO0 SDA/SPS
IO1
NTC/IO2
V
COIN
/IO3
V
FILTER
MCLR
8
R8
3
SR
9
100 nF
GND
10
VM
C32
1
IO4
11
470
SAFETY
IC
IO5
12
2
V
DD
2
R32
U2
S8241A
1
CMSZDA5V6
IO6
13
3
D1
16
1
2
3
4
5
14
20
20
R15
R14
240
240
R21
R20
B+
C
D
B-
PACK CONNECTION
C2
100 nF
C3
100 nF
20K
Q1
2
3
R31
1.0K
EXT. THERMISTOR INPUT
COIN CELL INPUT
NTC *
NVR
V
COIN
*
240
R2
* GROUND IF NOT USED
20
R5
R4
PS810 APPLICATION SCHEMATIC – PS810-BASED BATTERY PACK
TPCS8209
DS21904C-page 3
PS810
PS810
1.2
Bill of Materials
PS810 BILL OF MATERIALS
Symbol
Description
Raw PCB, PS8110
C10
Capacitor, Ceramic, 1.0 nF,
25V, +/-10%, X7R dielectric,
0402
Capacitor, Ceramic, 100 nF,
16V, +/-10%, X7R dielectric,
0603
Dual Zener Diode, 5.6V,
+/-10%, 200 mW,
common anode, SOT-323
MOSFET, dual N-channel
Enhancement mode, 20V,
5A, TSSOP-8/4.4 mm body
width package
Mftr.
Microchip
Panasonic
Mftr. PN
04-826197 Rev. 1.1
ECJ-0EB1E102K
Supplier
Microchip
Digikey
Supplier PN
04-826197 Rev. 1.1
PCC102BQCT-ND
Qty
1
1
TABLE 1-3:
ID
1 04-826197 Rev. 1.1
Part Number
2 CC-0402-10X7R25-1.0NF-01
3 CC-0603-10X7R16-100NF-01
C2, C3,
C5, C32
Panasonic
ECJ-1VB1C104K
Digikey
PCC1762CT-ND
4
4 DZ-SOT323-10D-CMSZDA5V6-01 D1
Central Semi. CMSZDA5V6
Diodes Inc.
AZ23C5V6W-7
Toshiba
TPCS8209(TE12L)
Central Semi. CMSZDA5V6
Diodes Inc.
AZ23C5V6W-7
Digikey
TPCS8209CT-ND
1
5 QM-TSSOP844-DN-TPCS8209-01 Q1
1
6 RF-0402-5-20-01
(Note 1)
7 RF-0402-5-20K-01
(Note 1)
8 RF-0603-ITC25-221K-01
(Note 1)
9 RF-0603-5-1.0K-01
(Note 1)
10 RF-0603-5-470-01
(Note 1)
11 RF-0805-5-20-01
(Note 1)
12 RF-0805-5-240-01
(Note 1)
13 RF-1206-1-0.029-01
(Note 1)
14 UM-SOT235-4085-
S8241ABPMCGBPT2-01
15 UM-QFN164X4-2085-PS810-01
R14, R15 Resistor, film, 0402, 5%,
20 ohms
R4
R8
R31
R32
R5
R2, R20,
R21
R9
U2
Resistor, film, 0402, 5%,
20 kOhms
Resistor, film, 0603, 1%,
232 kOhms, 25 ppm TC
Resistor, film, 0603, 5%,
1.0 kOhms
Resistor, film, 0603, 5%,
470 ohms
Resistor, film, 0805, 5%,
20 ohms
Resistor, film, 0805, 5%,
240 ohms
Resistor, metal strip, 1206,
1%, 0.020 ohms
Panasonic
Panasonic
Susumu Co.
Ltd.
Panasonic
Panasonic
Panasonic
Panasonic
Vishay
ERJ-2GEJ200X
ERJ-2GEJ203X
RR0816P-2213-D-34D
ERJ-3GEYJ102V
ERJ-3GEYJ471V
ERJ-6GEYJ200V
ERJ-6GEYJ241V
Digikey
Digikey
Digikey
Digikey
Digikey
Digikey
Digikey
P20JCT-ND
P20KJCT-ND
RR08P221KDCT-ND
P1.0KGCT-ND
P470GCT-ND
P20ACT-ND
P240ACT-ND
WSL1206-0.020-1%-R86
S-8241ABPMC-GBP-T2
(Note 2)
PS810
2
1
1
1
1
1
3
1
1
WSL1206-0.020-1%-R86 Vishay
S-8241ABPMC-GBP-T2
(Note 2)
PS810
Seiko
Instruments
Microchip
IC, Battery Protection Circuit, Seiko
Li Ion, 1-cell, -40°C to +85°C, Instruments
SOT23-5 package
IC, Low-Voltage Fuel Gauge, Microchip
-20°C to +85°C, QFN-16/
4.0x4.0 mm package
U1
1
Note
1:
2:
Resistor sizes shown are minimum recommended sizes for the application.
Other variants of the S-8241A series, with different trip points, are also available. Consult the S-8241A series data sheet.
DS21904C-page 4
©
2006 Microchip Technology Inc.
PS810
2.0
ARCHITECTURAL OVERVIEW
2.5
RAM Memory
The PS810 contains a complete analog “front-end” for
battery monitoring as well as an embedded micro-
controller, with supporting memory, for control,
measurement
accumulation,
calculation
and
communications. Major functions within the PS810
include:
•
•
•
•
•
•
•
Voltage Regulator
Precision Time Base
Temperature Sensor
4K x 16 Flash Memory
512-byte RAM Memory
15-bit plus sign Analog-to-Digital (A/D) Converter
SMBus/I
2
C™ or Single Pin Serial
Communications Interface
• PIC18 Microcontroller
Figure 1-1 is a block diagram of the internal circuitry of
the PS810. Figure 1-2 is a schematic diagram that
depicts the PS810 in a typical single cell lithium ion
application. The function of each of the blocks listed
above is summarized in the following sections.
512 bytes of general purpose RAM memory is provided
for storage of temporary parameters.
2.6
A/D Converter
The PS810 incorporates an integrating sigma-delta
A/D converter together with an analog that has inputs
for charge and discharge current, cell voltage, coin cell
voltage, the on-chip temperature sensor and an off-chip
thermistor. The converter can be programmed to per-
form a conversion with resolutions of 8 to 15 bits + sign,
while utilizing either a single-ended +300 mV or a
differential ±150 mV reference.
2.7
SMBus/I
2
C™ or Single Pin Serial
Communications Interface
This communications port for the PS810 is selectable
as a 2-pin industry standard SMBus/I
2
C or a single pin
interface. All commands, status and data are read or
written from the host system via this interface.
2.7.1
SMBus/I
2
C
2.1
Internal Voltage Regulator
The PS810 incorporates an internal voltage regulator
that supports 1-cell lithium pack configurations. The
internal regulator draws power directly from the VC1
input. No other external components are required to
regulate circuit voltage.
The two pin communication interface uses one clock
pin and one data pin and is compatible with the industry
standard System Management Bus (SMBus) and the
Inter IC Communication Bus (I
2
C).
2.7.2
SINGLE PIN SERIAL INTERFACE
2.2
Precision Time Base
The integrated precision time base is a highly accurate
RC oscillator that provides precise timing for the sigma-
delta A/D and for the on-chip elapsed time counters
without the need for an external crystal. This time base
is trimmed during manufacturing to a nominal
frequency of 512 kHz.
The Single Pin Serial (SPS) interface consists of one pin
only: the SDA/SPS pin (pin 14). This communication is
an asynchronous return-to-one protocol. The timing of
the driven low pulses defines the communication.
2.8
PIC18 Microcontroller
2.3
Temperature Sensor
An integrated temperature sensor is provided that can
eliminate the need for an external thermistor. As an
option, a connection is provided for an external
thermistor for applications where the battery cell is
physically separated from the PS810.
The PIC18 is a high-performance, CMOS, fully static
8-bit microcontroller. The PIC18 employs an advanced
RISC architecture. This device has enhanced core
features, such as 31 level deep stack and multiple
internal and external interrupt sources. The separate
instruction and data buses of the Harvard architecture
allow a 16-bit wide instruction word with a separate 8-bit
wide data bus. The two-stage instruction pipeline allows
all instructions to execute in a single cycle, except for
program branches, which require two cycles. A total of
75 instructions are available.
2.4
Flash Memory
4K x 16 of Flash memory is incorporated for storage of
nonvolatile parameters, such as PowerSmart
®
3D cell
models, fuel gauge algorithms and application specific
data.
©
2006 Microchip Technology Inc.
DS21904C-page 5
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