SSC SS6781BGSTB

SS6781B
Battery Charge Controller
FEATURES
DESCRIPTION
Fast Charge Control of NiMH/NiCd Batteries,
even with a Fluctuating Charging Current.
Fast Charge Termination by: ∆T / ∆t , −∆V ,
0 ∆V , Safety Timer, Maximum Temperature,
Maximum Voltage.
Linearly Adjustable ∆T / ∆t Detection Slope and
Safety Timer.
Adjustable Peak Voltage Timer for 0 ∆V .
Battery Voltage Protection Range Selectable.
Selectable Battery Temperature Protection
Mode.
Protection against Battery Voltage and Battery
Temperature Faults.
Selectable LED Display Mode for Battery Status.
Five Pulsed Trickle Charge Modes.
Discharge-before-Charge Function Available for
Eliminating Memory Effect.
Quick and Easy Testing for Production.
16-pin DIP or SO Packages.
APPLICATIONS
Battery Fast Chargers for:
Mobile Phones.
Notebook and Laptop Personal Computers.
Portable Power Tools and Toys.
Portable Communication Equipments.
Portable Video & Stereo Equipments.
100
Charge Current = 600 mA
Cell Capacity = 550 mA
NiMH Battery
80
1.45
Cell Voltage
60
1.35
40
1.25
Temperature (°C)
Cell Voltage (V)
1.55
Temperature
1.15
0
10
20
30
40
50
Charge Time (min.)
60
20
Fig. 1 Battery Charging Characteristics Resulting from
an
SS6781B-Controlled
Charger
Fluctuating Charging Current
with
a
The SS6781B fast charge controller IC is
designed for intelligent charging of NiMH or NiCd
batteries without the risk of overcharge. −∆V
Detection (-0.25%), 0 ∆V detection (peak voltage
timer) and ∆T / ∆t detection are the primary
methods employed by the SS6781B to terminate
fast charge. The fast charge can also be cut off by
maximum battery voltage and maximum battery
temperature detection along with the safety timer
to prevent charging under fault conditions of the
charging system or the battery itself.
Both ∆T / ∆t and −∆V detection methods have
been proved powerful in terminating fast charging
for NiMH and NiCd batteries. The SS6781B
utilizes the combination of these two methods to
achieve reliable decision of ending fast charge and
prevent misacting caused by using −∆V detection
alone under certain conditions. Fig. 1 shows an
example of charging curve of a battery charged by
a fluctuating current from a NiMH battery charger,
which uses the SS6781B controller IC to achieve
optimal charging. This technique, in cooperating
with the 0 ∆V detection (peak voltage timer), is
particularly suitable for NiMH batteries, whose
voltage drop is hardly significant yet temperature
rises rapidly. The ∆T / ∆t or −∆V detection
circuitry may be disabled independently for
different applications, such as system-integrated
chargers, chargers with varying charge current, or
battery packs lack of temperature sensing
thermistor.
The safety timer period, mode of battery
temperature protection, battery voltage protection
range, pulsed trickle charge duty, and LED display
mode are all adjustable or selectable.
Discharge-before-charge function is included to
get rid of memory effect of NiCd batteries without
Pb-free; RoHS-compliant
01/31/2008 Rev.1.00
www.SiliconStandard.com
1
SS6781B
the risk of overdischarging. Test mode is provided
for charger manufactures to dramatically reduce
production test time.
TYPICAL APPLICATION CIRCUIT
D1
R1
1K
C2
220µH
1µF
2
3
C1
4
U1
DC
BOOST
DE
IS
CF
VCC
GND
FB
470P
IN4148
7
RS 0.3/1W
6
+
5
2
Q1
C10
C7
0.1µF
C9
4.7µF
91K
1
47nF
MPS2222A
R15
3
680
4
5
6
BAT1
C3
220µF
SS6563
R9
1N5819
YELLOW
R10
100K
+
D4
D3
8
PB SW
LED1
R8
300K
0.1µF
270
20/5W
IN5819
C5
**BATTERY
390K
1
+
C4
220µF
R5 120/0.5W
R4
D2
L1
R7
RX
THERMISTOR
IN4148
SW1
R3
R2
RY
R14
+
C6
0.1µF
C8
C11
200K
0.1µF
100µF
7
R6
8
50K
R11
100K
U2
PEAK
VBT
DSW
ICON
LED2
DIS
VTS
VCC
LED1
GND
ADJ
SEL1
SEL3
SEL2
TMR
MODE
LED2
LED3
GREEN
RED
R12
16
15
R16
680
R17
680
14
13
12
11
10
9
SS6781B
5.1K
U3
VIN
11~15V
VIN
+
C12
R13
470K
78L05
VOUT
GND
1µF
Q2
MMBT2222A
+
C13
10µF
**3~5 NiMH/NiCd cells.
Note: Charge Current=0.3/RS Ampere
Safety Timer: 80min
Battery Charge Circuit for Fluctuating Charging Current Application
ORDERING INFORMATION
SS6781BXXXX
PIN CONFIGURATION
TOP VIEW
PACKING TYPE
TR: TAPE & REEL
TB: TUBE
PACKAGE TYPE
N: PLASTIC DIP
S: SMALL OUTLINE
C: COMMERCIAL
G: LEAD FREE COMMERCIAL
Example: SS6781BCSTR
in SO-16 Package & Tape & Reel Packing Type
PEAK
1
16
DSW
VBT
2
15
ICON
DIS
3
14
LED2
VTS
4
13
LED1
VCC
5
12
GND
ADJ
6
11 SEL1
SEL3
7
10
SEL2
TMR
8
9
MODE
(CN is not available in TR packing type)
SS6781BGSTR
in SO-16 Lead Free Package & Tape & Reel
Packing Type
01/31/2008 Rev.1.00
www.SiliconStandard.com
2
SS6781B
ABSOLUTE MAXIMUM RATINGS
Supply Voltage
5.5V
DC Voltage Applied on any pin
5.5V
20mA
Sink current of ICON pin, LED1 and LED2 pin
-40°C~ 85°C
Operating Temperature Range
Storage Temperature Range
-65°C~ 150°C
Junction Temperature Range
125°C
Lead Temperature (Soldering 10 sec)
260°C
Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
TEST CIRCUIT
VCC
VOLTAGE
SOURCE
-
+
YELLOW
R1
560
-
+
VOLTAGE SOURCE
VCC (5V)
VCC
V1 (0.95V)
V2 (3V)
5.1K
PEAK
DSW
VBT
ICON
DIS
LED2
VTS
LED1
R3
ORANGE
560
R4
GREEN
560
R5
RED
560
SS6781B
VCC
GND
ADJ
SEL1
VCC
SEL3
SEL2
VCC
TMR
MODE
VCC
VCC
R2
01/31/2008 Rev.1.00
www.SiliconStandard.com
3
SS6781B
ELECTRICAL CHARACTERISTICS (TA=25°C, VCC=5V, unless otherwise specified.)
(Note1)
SYMBOL
MIN.
TYP.
MAX.
UNIT
Supply Voltage
VCC
4.5
5.0
5.5
V
Supply Current
ICC
PARAMETER
TEST CONDITIONS
Battery Low
During Initial Timer
After Initial Timer
(SEL3>3V)
(SEL3<2V)
Battery High
(SEL3>3V)
(SEL3<2V)
Voltage Protection Limit
VBT
Temperature High
Temperature Sense Limit
Temperature Low
Output impedance of DIS Pin
VTS
1.1
mA
0.11
0.16
0.21
0.63
1.1
0.69
1.2
0.75
1.30
2.6
2.7
2.80
1.9
2.0
2.10
1.35
1.45
1.55
3.5
3.6
3.70
50
100
Ω
25
50
Ω
ZDIS
V
V
LED1, LED2, ICON pins
Output Impedance
ON
OFF
Source Current Capability
1
SEL3 pin
ISEL3
5.5
DSW pin
IDSW
90
MODE, PEAK, SEL1,
SEL2 pins
Input Impedance
Recommended External
Temperature detective
function is enabled.
Battery’s type is
GP180AAHC
(Note2, Note3, Note4)
-∆V Detection
Peak Value
Level
kΩ
1
RTMR
Resistor of TMR pin
µA
300
VBT, VTS, ADJ pins
Battery Charge Current
MΩ
w.r.t.
MΩ
0.9
5.1
27
kΩ
0.25
0.8
1
C
-0.25
%
* w.r.t.: with respect to
01/31/2008 Rev.1.00
www.SiliconStandard.com
4
SS6781B
Note 1: Specifications are production tested at TA=25℃. Specifications over the -40℃ to 85℃ operating
temperature range are assured by design, characterization and correlation with Statistical Quality
Controls (SQC).
Note 2: Guaranteed by battery’s specification.
Note 3: Disable the temperature detective function is not recommended. Disable the temperature detection
function may cause the detection error in some conditions. (For example, battery over discharge)
Note 4: Generally the electrical current for charge or discharge is expressed in terms of a multiplier of C. For
example, if the capacity is 1800mAh, we have the following: 0.1C=0.1*1800=180mA
01/31/2008 Rev.1.00
www.SiliconStandard.com
5
SS6781B
▓ TYPICAL PERFORMANCE CHARACTERISTICS
(TA=25°C, R2=5.1KΩ,
VCC=5V, refer to Test Circuit)
81.5
81.0
Safety Timer (min)
Supply Current (mA)
1.08
1.02
0.96
0.90
80.0
79.5
79.0
78.5
0.84
4.4
4.6
4.8
5.0
5.2
VCC (V)
78.0
4.4
5.4
Fig. 2 Supply Current vs. Supply Voltage
Supply Current (mA)
4.0
3.8
3.6
4.4
5.0
VCC (V)
5.2
5.4
5.6
4.6
4.8
5.0
5.2
5.4
1.00
0.95
0.90
0.85
0.80
0
5.6
VCC (V)
Fig. 4 LED Flashing Frequency vs.
Supply Voltage
20
40
Temperature (°C)
60
80
Fig.5 Supply Current vs. Temperature
82
5.0
81
4.8
Frequency (Hz)
Safety Timer (min)
4.8
1.05
4.2
80
79
78
77
76
75
4.6
Fig. 3 Safety Timer vs. Supply Voltage
4.4
Frequency (Hz)
80.5
4.6
4.4
4.2
4.0
3.8
3.6
0
20
40
60
80
Temperature (°C)
Fig. 6 Safety Timer vs. Temperature
01/31/2008 Rev.1.00
3.4
-20
0
20
40
Temperature (°C)
60
80
Fig. 7 LED Flashing Frequency vs. Temperature
www.SiliconStandard.com
6
SS6781B
TYPICAL PERFORMANCE CHARACTERISTICS
2.80
(Continued)
2.28
2.76
2.72
VBT (V)
VBT (V)
2.16
2.68
2.04
2.64
1.92
2.60
0
Fig. 8
20
40
60
80
0
Temperature (°C)
VBT (High) Limit vs. Temperature
(SEL3>3V)
Fig. 9
0.20
Output Impedance (Ω)
VBT (V)
0.16
0.14
0
20
40
60
60
80
Temperature (°C)
VBT (Low) Limit vs. Temperature
(During Initial Timer)
30
27
24
21
80
0
20
40
60
80
20
40
60
80
Temperature (°C)
Fig.11 Output Impedance vs. Temperature
(LED1, LED2, ICON Pins)
4.0
1.55
3.8
1.50
VTS (V)
VTS (V)
Fig.10
3.6
3.4
3.2
40
Temperature (°C)
VBT (High) Limit vs. Temperature
(SEL3<2V)
33
0.18
0.12
20
1.45
1.40
0
20
Fig.12
Temperature (°C)
VTS (Low Temp) Limit vs.
Temperature
01/31/2008 Rev.1.00
40
60
80
1.35
0
Temperature (°C)
Fig.13 VTS (High Temp) Limit vs.
Temperature
www.SiliconStandard.com
7
SS6781B
1.5
0.84
1.4
VBT (V)
VBT (V)
0.80
0.76
0.72
0.68
1.3
1.2
1.1
0.64
0
20
40
60
1.0
80
Temperature (°C)
Fig. 14 VBT (Low) Limit vs. Temperature
(SEL3>3V, After Initial Timer)
0
20
40
60
80
Fig.15
Temperature (°C)
VBT (Low) Limit vs. Temperature
(SEL3<2V, After Initial Timer)
VCC
TMR
BLOCK DIAGRAM
PEAK
Peak Voltage
Timer Control
SEL3
MODE
MODE
Selection
GND
Bandgap
Reference &
Voltage
Regulator
Battery Voltage &
Temperature
Portection Setting
Charge Control
SEL1
SEL2
LED‘s Display
& Trickle Pulse
Duty Setting
ADJ
∆T/∆t Detection
Setting
Battery Temp.
Protection
VTS
01/31/2008 Rev.1.00
State Machine
LED2
Oscillator
Display
Control
Unit
LED1
ICON
Charge
Control Unit
DIS
13-bit
A/D
Battery
Voltage
Protection
Discharge
Control Unit
DSW
VBT
www.SiliconStandard.com
8
SS6781B
PIN DESCRIPTIONS
PIN 1: PEAK- Tri-level input, determining the
period of peak voltage timer.
(See 0∆V cut-off section in
application informations.)
PIN 2: VBTPIN 3: DIS-
PIN 4: VTS-
Divided battery voltage input to
sense the battery voltage.
Push-pull output, used to
control an external transistor to
discharge the battery. DIS is
active
high
when
the
SS6781B
enters discharge
mode.
The battery cell temperature is
represented as a voltage input
to the SS6781B at this pin.
The acceptable voltage range
of VTS pin is 0.29VCC to
0.72VCC.
The
battery
temperature is regarded as too
high if the voltage of VTS pin is
lower than 0.29VCC, and is
otherwise regarded as too low
if the voltage of VTS pin is
higher than 0.72VCC.
PIN 5: VCC-
Power supply input at 5V±10%.
PIN 6: ADJ-
For adjusting the slope of ∆T/∆t.
Acceptable voltage range for
this pin is approximately 0.28V
to 3.8V. If voltage higher than
VCC-0.3V, the function of
∆T/∆t detection is disabled.
PIN 7: SEL3-
the
acceptable
Determine
voltage range of VBT pin and
mode
of
temperature
protection function.
01/31/2008 Rev.1.00
Determine the period of safety
timer with an external resistor
connected to GND.
the
mode
of
PIN 9: MODE- Determine
operation for the SS6781B.
PIN 8: TMR-
PIN 10: SEL2 - Tri-level inputs, that jointly
control the LED display mode
and the duty of trickle charge
after the completion of fast
charge.
PIN 11: SEL1- The same as Pin 10.
PIN 12: GND-
Power ground.
PIN 13: LED1 &
PIN 14: LED2- Open-drained outputs used to
indicate the battery charging
status. Two modes of display
are available, depending on
the setting of SEL1 and SEL2
pins.
PIN 15: ICON- Open-drained output, used to
control the charging current to
the battery.
PIN 16: DSW- Controlling the function of
discharge- before- charge.
(See discharge- before- charge
subsection
in
application
informations).
www.SiliconStandard.com
9
SS6781B
APPLICATION INFORMATIONS
discharge is finished. The application circuit is
included in TYPICAL APPLICATION CIRCUIT.
THE SS6781B OPERATION
Power-on and Battery Pre-qualifying
When power is first applied to the SS6781B, all
internal digital circuit blocks of the SS6781B are
reset by the internal power-on-reset circuitry and
output LEDs (depending on the setting of SEL1 and
SEL2 pins) flash 3 times to indicate the initiation of
power-on. The internal control unit then examines
the battery condition through the VBT and VTS
pins.
The acceptable limits of VBT pin is determined by
the input voltage of SEL3 pin and the acceptable
temperature sense voltage window for VTS pin is
0.29 VCC to 0.72 VCC. If the voltage of VBT pin fails
to fall within the predetermined acceptable limits,
the SS6781B enters a charge-suspending mode, in
which all the internal circuitry remains in reset state.
If the voltage of VTS pin is outside the 0.29 VCC to
0.72 VCC window, action of SS6781B is determined
by the input voltage of SEL3 pin.
Discharge-Before-Charge
The SS6781B provides the function of
discharge-before-charge to precondition NiCd
batteries which suffer from memory effect. This
function can only be activated after the
pre-qualification of battery voltage and temperature,
yet before the charge completion is registered for
the fast charge cycle.
To trigger this function, DSW pin has to be biased
to GND for over 0.18 second. After discharge
begins, LED1 and LED2 pins are both off, ICON
pin is on, and DIS pin goes high to activate an
external circuit to discharge the battery until the
voltage of VBT pin falls below 0.9V (or 0.69V,
depending on the input voltage of SEL3 pin) or
DSW pin is biased to GND for over 0.18 second
again. Fast charge will automatically start after
01/31/2008 Rev.1.00
Fast Charge
After the battery passes fault checks and required
discharging of the battery is completed, fast
charging begins while initial timer and safety timer
of the SS6781B start counting. Functions of -∆V
detection, peak voltage timer, ∆T/∆t detection,
and maximum battery voltage are, however,
disabled temporarily until the initial timer period in
the initial stage of a charge cycle elapses. The
initial timer period is equal to 1/80 of safety timer.
Since the low limit of acceptable VBT voltage is
only about 0.16V during the initial timer period,
even deeply discharged batteries can easily qualify
to be fast charged subsequently.
In the course of fast charge, the SS6781B
constantly monitors the voltages at VBT and VTS
pins. The fast charge process is switched to trickle
charge when any one of the following situations is
encountered, which are explained below:
Negative delta voltage (-∆V)
Peak voltage timer (0 ∆V )
Delta temperature/ delta time (∆T/∆t)
Maximum charge time
Maximum battery voltage
Maximum battery temperature
-∆V Cutoff
The SS6781B makes a voltage sampling at VBT
pin every 4 seconds when safety timer period is set
equal to 80 minutes. If a negative delta voltage of
0.25% compared to its peak value is detected at
VBT pin, the fast charge cycle is terminated.
0∆V Cutoff
If the battery voltage stays at its peak value or
decreases very slowly for the duration determined
by the peak voltage timer, which is in turn
www.SiliconStandard.com
10
SS6781B
determined by PEAK pin voltage, the fast charge
action is terminated.
∆T/∆t Cutoff
The ∆T/∆t detection of the SS6781B is performed
by sensing the decrease of VTS pin voltage in a
specific timer interval dictated by the safety timer.
The fast charging terminates when the decrease of
VTS pin voltage in 56 seconds exceeds the
predetermined value set by ADJ pin input. This time
interval of 56 seconds is based on the assumption
that voltage of VTS pin is sampled once for every 8
seconds, which is also determined by safety timer.
Functioning of -∆V detection and peak voltage timer
(0 ∆V ) can be disabled if the MODE pin is biased to
GND. Functioning of ∆T/∆t detection can be
disabled if the voltage of ADJ pin is higher than VCC
- 0.3V.
loss of charge due to battery self-discharging. The
duty cycle is controlled by the setting of SEL1 and
SEL2 pins.
The functions and charging states control
mentioned above are illustrated in the function flow
chart of SS6781B (Fig. 16)
DESIGN GUIDE
Selecting Peak Voltage Timer (0∆V)
The voltage of PEAK pin along with safety timer
determines the period of peak voltage timer. It can
be selected according to the following table:
TABLE 1
Maximum Safety Timer Cutoff
The maximum fast charge period is determined by
the safety timer, which is set by a resistor
connected from TMR pin to GND. Safety timer, -∆V
sampling rate, and ∆T/∆t sampling rate will be
longer if the resistor value is larger. When the value
of the resistor is 5.1KΩ, the safety timer period
equals 80 minutes. This can be verified by biasing
MODE pin to VCC and the measured frequency on
DSW pin should be around 32.8 KHz. After the
safety timer period is finished, the fast charge
action is terminated.
PEAK PIN
PEAK VOLTAGE TIMER
VCC
1.5% of safety timer
Floating
3.7% of safety timer
GND
6% of safety timer
Battery Voltage Measurement
The SS6781B measures the battery voltage
through VBT pin, which is connected to battery
positive terminal through a resistor-divider network,
as shown in Fig. 17. The input voltage of SEL3 pin
determines the acceptable limit of divided battery
voltage.
VBAT
RA
RB
+
C5
2
VBT
100K
4.7µF
The SS6781B guards against the maximum limits
for battery voltage and temperature during fast
charging. If either of these limits is exceeded, fast
charge action is terminated.
R5
C6
0.1µF
Maximum Voltage and Temperature Cutoff
AIC1781B
Fig. 17 Battery Voltage Divider
Trickle Charge
There are five different selectable duty cycles for
trickle charge after the fast charge to prevent the
01/31/2008 Rev.1.00
www.SiliconStandard.com
11
SS6781B
Power ON
LED Flash 3 Times
If
VBT in Normal
Range
No
Yes
Yes
If
VNTC<0.72 VCC
LED's Display Abnormal,
ICON ON,
Safety Timer Reset
No
If
SEL3>VCC-0.3V
or VCC/2-0.4V>SEL3
>1.4V
No
No
If
SEL3>VCC-0.3V
or VCC/2-0.4V>SEL3
>1.4V
Yes
∆T/∆t Disabled
No
Yes
If VNTC>0.29VCC
LED's Display,
Abnormal,
ICON ON,
Safety Timer Reset
Yes
No
If
Discharge
Finished
Yes
If
Discharge
Enabled
Battery Replacement
Yes
Yes
No
No
LED's Display Fast Charge, ICON OFF
Safety Timer Counts
If
Initial Timer
Finished
∆T/∆t Detector,
-∆V Detector,
Peak timer are all
Disabled
No
Yes
If
Peak Timer Period
has Finished
Yes
No
If
0.25% Decline of VBT
is Detected
Yes
No
If ∆T/ ∆ t
has Reached
LED's Display
Battery Fulll,
Fast Charge
Finished,
Trickle charge
Starts
Battery Replacement
Yes
Yes
No
No
No
If
Safety Timer Period
has Finished
Yes
Fig. 16 Function Flow Chart of SS6781B
01/31/2008 Rev.1.00
www.SiliconStandard.com
12
SS6781B
BATTERY
CELLS
RA/RB
2~4
2
240
120
3~6
3.3
300
91
4~8
4.9
300
62
RA (KΩ)
RB (KΩ)
5~10
6.4
300
47
6~12
7.8
310
39
8~16
10.8
390
36
The SS6781B employs a negative temperature
coefficient (NTC) thermistor to measure the
battery’s temperature. The thermistor is inherently
nonlinear with respect to temperature. To reduce
the effect of nonlinearity, a resistor-divider network
in parallel with the thermistor is recommended. A
typical application circuit is shown in Fig. 18.
VCC
VBAT
4
For SEL3 < (VCC/2) -0.4V, the suggested divider
resistance of RA and RB for the corresponding
number of battery cells are as below:
TABLE 3
BATTERY
CELLS
RA/RB
RA(KΩ)
RB (KΩ)
2
1
240
240
3
2
240
120
4
3
240
80
5
4
300
75
6
5
300
60
8
7
360
51
10
9
360
40
12
11
390
36
16
15
410
27
01/31/2008 Rev.1.00
5
VCC
Rx
C7
0.1µF
TABLE 2
Battery Temperature Measurement
Thermistor
For SEL3 > (VCC/2) + 0.4V, the suggested divider
resistance of RA and RB for the corresponding
number of battery cells are as below:
VTS
AIC1781B
Ry
12
GND
Fig. 18 Battery Temperature Sense Circuit
with a Negative Temperature Coefficient
(NTC) Thermistor
www.SiliconStandard.com
13
SS6781B
The calculation for Rx and Ry in the circuit is as
following.
Ry//RTH
0.29 VCC =
x VCC
Rx + (Ry// RTH)
RTH= The resistance of thermistor at upper limit of
temperature protection.
Ry//R TL
0.72 VCC =
x VCC
Rx + (Ry// R TL )
RTL= The resistance of thermistor at lower limit of
temperature protection.
Substitution and rearranging the equations yield
Rx= 2.061 ×
Ry =
RTL × RTH
66
5.7
31.6
67
5.5
29.5
68
5.3
27.5
69
5.2
25.8
70
5.0
24.3
TABLE 5 Values of Rx and Ry at TL = -10°C
TH (°C)
Rx (KΩ)
Ry (KΩ)
45
11.4
95.6
46
11.0
85.0
47
10.6
76.2
48
10.2
68.9
49
9.8
62.8
50
9.5
57.5
RTL − RTH
5. 3 × RTL × RTH
51
9.1
52.9
52
8.8
48.8
RTL − 6. 3RTH
53
8.5
45.3
54
8.2
42.1
55
7.9
39.4
56
7.6
36.8
57
7.4
34.6
58
7.1
32.5
59
6.9
30.7
60
6.7
29.0
If temperature characteristic of the thermistor is like
that of SEMITEC 103AT-2, the resistance of Rx and
Ry is tabulated for different TL and TH as below.
(Note: TL is lower temperature limit and TH is upper
temperature limit.)
TABLE 4 Values of Rx and Ry at TL = 0°C
TH (°C)
Rx(KΩ)
Ry (KΩ)
61
6.4
27.4
50
10.1
551.1
62
6.2
26.0
51
9.7
300.7
63
6.0
24.6
52
9.4
204.8
64
5.8
23.4
53
9.0
153.9
65
5.6
22.2
54
8.7
122.8
55
8.4
101.8
56
8.1
86.5
57
7.8
75.0
58
7.5
66.0
59
7.2
58.7
60
7.0
52.8
61
6.8
47.8
62
6.5
43.6
63
6.3
39.9
64
6.1
36.8
65
5.9
34.0
01/31/2008 Rev.1.00
Setting the ADJ Pin Voltage
The slope of ∆T/∆t detection is determined by ADJ
pin voltage of the SS6781B.
The calculation of ADJ pin voltage is shown in the
following procedure followed by an example.
www.SiliconStandard.com
14
SS6781B
Procedure
120 min. (0.67C)
(a) First, determine the temperature protection
limits TH and TL. Then, substitute TH & TL into
the following equation:
∆V TS
0.72 V CC − 0. 29 V CC 0. 43 V CC
=
=
∆TBASE
TH − TL
TH − TL
(b) Determine the safety timer to obtain the value of
∆tBASE .
56(sec.)
∆tBASE(sec.) =
× Safety Timer (min .)
80(min .)
160 min. (0.5C)
200 min. (0.4C)
240 min. (0.33C)
∆T / ∆t
S.T.
VADJ = 30 ×
∆VTS ∆T
×
× ∆tBASE
∆TBASE ∆t
(a) Let TH=50°C, TL=0°C, VCC =5V. We have
∆VTS
0.43 × 5
=
= 0.043V/° C
∆TBASE
50 − 0
which means that VTS decreases 43mV as
temperature rises 1°C.
(b) If safety timer is equal to 80 minutes, ∆tBASE is
then 56 seconds.
(c) If fast charge should be terminated when
temperature rises 1°C in 60 seconds, then
1
∆T/∆t =
= 0.0166
60
(d) VADJ =30 x 0.043x 0.0166 x 56 = 1.2(V)
If the temperature range is from 0°C to 50°C,
the voltage of VADJ under different setting
conditions should be set as tabulated below.
TABLE 6 ADJ pin Voltage (TL=0°C, TH=50°C)
S.T.
40 min. (2C)
80 min. (1C)
01/31/2008 Rev.1.00
0.75
1.0
1.25
(°C/min.) (°C/min.) (°C/min.)
0.45
0.90
0.60
1.20
2.25
3.01
3.76
120 min. (0.67C)
160 min. (0.5C)
200 min. (0.4C)
0.75
1.0
1.25
(°C/min.) (°C/min.) (°C/min.)
0.37
0.75
1.12
1.50
1.88
2.25
0.50
1.00
1.50
2.00
2.50
3.01
0.62
1.25
1.88
2.50
3.13
3.76
VBT Range and Temperature Protection
The acceptable voltage range of VBT pin and
mode of temperature protection function is
determined by the voltage of SEL3 pin, shown as
the following:
Example
∆T / ∆t
80 min. (1C)
240 min. (0.33C)
(d) Calculate the value of VADJ
1.80
2.40
3.01
3.61
A similar table for temperature range from 0°C to
60°C is as below.
TABLE 7 ADJ Pin Voltage (TL=0°C, TH=60°C)
40 min. (2C)
(c) Determine the expected slope of ∆T / ∆t at
which temperature rises y°C in x seconds and
fast charge is subsequently cut off.
∆T y
=
∆t
x
1.35
1.80
2.25
2.70
0.75
1.50
(a) SEL3 > VCC - 0.3V
Acceptable VBT Range:
Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V
Temperature Protection Mode:
Entering charge-suspending mode when
temperature is either too low or too high,
same as abnormal battery voltage. Latch for
charge-suspending function is provided for
high temperature protection, but not for low
temperature protection.
(b) VCC - 1.4V> SEL3 >
V cc
+ 0.4V
2
Acceptable VBT Range:
Before initial timer: 0.16V~2.7V
After initial timer: 0.69V~2.7V
Temperature Protection Mode:
If temperature is too high, battery charging is
regarded as completed. If temperature is too
www.SiliconStandard.com
15
SS6781B
low, function of ∆T/∆t detection is disabled, just
as thermistor is not existing.
120
100
V cc
(c)
- 0.4V>SEL3 >1.4V
2
RTIM (Kohm)
80
Acceptable VBT Range:
Before initial timer: 0.16V~2V
After initial timer: 1.2V~2V
Temperature Protection Mode:
Entering charge-suspending mode when
temperature is either too low or too high, same
as abnormal battery voltage. Latch for
charge-suspending function is provided for high
temperature protection, but not for low
temperature protection.
60
40
20
0
0
Fig. 19
TABLE 8
600
800
1000
1200
1400
Safety Timer vs. RTMR
RTMR (KΩ)
OSC.
Freq.(KHz)
Safety timer
(min.)
0.9
2.2
3.5
5.1
7.8
10.9
17.5
26.2
2100
1049.6
704
518.4
353.6
264
174.4
116.8
20
40
60
80
120
160
240
360
If temperature is too high, battery charging is
regarded as completed. If temperature is too
as thermistor is not existing.
400
Safety Timer (min.)
(d) 0.3V> SEL3
Acceptable VBT Range:
Before initial timer: 0.16V~2V
After initial timer: 1.2V~2V
Temperature Protection Mode:
low, function of ∆T/∆t detection is disabled, just
200
Selecting Mode of Operation
The SS6781B provides three modes of operation:
normal, test, and AC mode determined by the
Setting the Period of Safety Timer
The SS6781B provides a method for linearly
adjusting the period of safety timer with an external
resistor connected from TMR pin to GND. The
relation between safety timer length and the
external resistor (RTMR) is shown in Fig. 19. The
table following shows the resistor values for some
of the commonly chosen safety timer periods. Also
shown in the table are their corresponding
oscillator frequencies.
setting of MODE pin according to TABLE 9. The
AIC1781B will operate normally when the MODE
pin
is
left
floating
(a
0.1µF
capacitor
is
recommended to be tied to MODE pin if the charge
circuit works in a noisy environment). When the
MODE pin is biased to GND, the function of -∆V
detection is disabled. When the MODE pin is
biased to VCC, the SS6781B enters the test mode.
The test mode can be used to significantly reduce
production test time. For relevant information
please contact AIC directly.
01/31/2008 Rev.1.00
www.SiliconStandard.com
16
SS6781B
TABLE 9
The Operating Mode of SS6781B
MODE pin
Mode
VCC
Test
Floating
AC
Power
ON
Function
Safety timer period scaled
down to 1/512....etc.
Normal Normal operation
GND
TYPE 2
–∆V detection disabled
The Mode of LED Display and Trickle Charge
The SS6781B provides two LED display modes
and five-pulsed trickle charge modes. The
tri-level inputs, SEL1 and SEL2 pins, as in the
TABLE 6 determine the modes of LED display
Fault
Charge
Fast
Charging Completed Conditions
LED1
1Hz
ON
OFF
4Hz
Flashing
LED2
1Hz
4Hz
Flashing
ON
OFF
Charging Current Control
As shown in the typical application circuit, the
SS6781B offers an open-drained output pin, ICON
pin, to control the charging current flow in fast
charge state and switch on to inhibit the charging
and trickle charge.
TABLE 10 Mode of LED Display and Trickle
Charge
current flow in fault conditions. When fast charge is
completed, the SS6781B enters the trickle charge
mode. In trickle charge mode, the ICON pin output
SEL1
Trickle Charge LED Display
Duty
Mode
SEL2
VCC
VCC
Floating
GND
N/A
1/32
1/64
Type 1
Type 1
Type 1
Floating
VCC
Floating
GND
1/128
1/256
N/A
Type 1
Type 1
Type 2
GND
VCC
Floating
GND
1/32
1/64
1/128
Type 2
Type 2
Type 2
SS6781B
provides
two
the table of trickle charge mode (TABLE 6), the
duty cycle is determined by the setting of SEL1
and SEL2 pins. The following table summarizes
how ICON pin corresponds to various charging
states.
Charge
Power
Fast
Fault
ON
Charging Completed Conditions
ICON
ON
OFF
See pin 10
& 11
ON
Test Mode
Display the Battery Charging Status
The
switches with predetermined duty cycle. Refer to
open-drained
Fig. 20 shows the timing diagram for externally
outputs, LED1 and LED2, to indicate the battery
controlled PEAK, ADJ, VBT, VTS, SEL1 and
charging status. Refer to the table of LED display
SEL2 pin voltages of a recommended SS6781B
mode (TABLE 10), depending on the setting of
test scheme, utilizing TEST mode function.
SEL1 and SEL2 pins, the outputs of LED1 and
Output waveforms of LED1, LED2 and ICON of a
LED2 pins are shown in the following table:
properly functioning SS6781B are also shown in
TYPE 1
the figure.
Fast
Power
Charge
Fault
ON
Charging Completed Conditions
LED1
1Hz
ON
OFF
OFF
LED2
OFF
OFF
ON
OFF
01/31/2008 Rev.1.00
www.SiliconStandard.com
17
SS6781B
TIMING DIAGRAM
Power
ON
VCC, SEL3, MODE=5V, RTMR=2.9kΩ, (DSW FREQ.=820KHz, 25 TIMES of 32.8K)
Init. PEAK TIMER TEST
PEAK
ADJ
-∆V DISABLE TEST
-∆V TEST
5V
SAFETY TIMER TEST
∆T/∆t TEST
0V
5V
1.12V
3V
<2.1V
(-0.15%)
2V
2V (-0.15%)
1.997V
2V
1.997V
1.95V
VBT
1.9V
1.5V
VTS
2V
1.997V
0V
2mV
Step/100mS
1.993V
(-0.35%)
4V
4V
4V
4V
2V
2V
2V
2V
1.97V
1.85V
(-2.15%)
OFF
LED1
ON
LED2
OFF
(-2.5%)
OFF
OFF
2mV
Step/100mS
OFF
ON
ON
3.2KHz
ON
ON
ON
ON
OFF
ICON
OFF
OFF
ON
SEL1
SEL2
TIME
Floating
Floating
VCC
Floating
0.1
0.14 0.12
0.28
0.2
0.12
3
4
0.32
Floating
GND
0.32
0.12
5
6
0.32
GND
Floating
0.5
0.7
0.24
GND
GND
0.4
2.14
8
9
Floating
Floating
0.1
0.02
(SEC.)
STAGE
1
2
0 0.14 0.26
0.54
0.74 0.86
1.18
Fig. 20
01/31/2008 Rev.1.00
1.5
7
1.62
1.94
2.64
3.14 3.38
3.78
10
5.92 6.02
6.04
Timing Diagram of SS6781B in Test Mode
www.SiliconStandard.com
18
SS6781B
PHYSICAL DIMENSIONS (unit: mm)
DIP-16
E
D
S
Y
M
B
O
L
GAUGE PLANE
DIP-16
MILLIMETERS
MAX.
MIN.
5.33
0.38
E1
A
A1
eA
A
A2
eB
b
A
D1
b2
A
e
c
L
A1
WITH PLATING
BASE METAL
0.38
A2
2.92
4.95
b
0.36
0.56
b2
1.14
1.78
c
0.20
0.35
D
18.66
19.69
D1
0.13
E
7.62
E1
6.10
7.11
e
2.54 BSC
eA
7.62 BSC
eB
SECTION A-A
8.26
L
10.92
2.92
3.81
Note:
1. Refer to JEDEC MS-001BB.
2. Dimension D does not include mold flash, protrusions or gate burrs.
Mold flash , protrusions or gate burrs shall not exceed 10 mil per
side
3. Dimension “D1” and “E1” do not include inter-lead flash or
protrusions.
4. Controlling dimension is millimeter, converted inch dimensions are
not necessarily exact.
01/31/2008 Rev.1.00
www.SiliconStandard.com
19
SS6781B
SOP-16 (300 mil)
D
A
h x 45°
E
e
H
S
Y
M
B
O
L
A
SOP-16(300mil)
MILLIMETERS
MIN.
MAX.
A
2.35
2.65
A1
0.10
0.30
B
0.33
0.51
C
0.23
0.32
D
10.10
10.50
E
7.40
SEE VIEW B
A1
A
e
B
0.25
C
WITH PLATING
7.60
1.27 BSC
H
10.00
h
0.25
0.50
L
0.40
1.27
0°
8°
θ
10.65
BASE METAL
SECTION A-A
GAUGE PLANE
SEATING PLANE
VIEW B
θ
L
Note:
1. Refer to JEDEC MS-013AA.
2. Dimension “D” does not include mold flash, protrusions or gate burrs. Mold
flash, protrusion or gate burrs shall not exceed 6 mil per side.
3. Dimension “E” does not include inter-lead flash or protrusions.
4. Controlling dimension is millimeter, converted inch dimensions are not
necessarily exact.
Information furnished by Silicon Standard Corporation is believed to be accurate and reliable. However, Silicon Standard Corporation makes no
guarantee or warranty, expressed or implied, as to the reliability, accuracy, timeliness or completeness of such information and assumes no
responsibility for its use, or for infringement of any patent or other intellectual property rights of third parties that may result from its
use. Silicon Standard reserves the right to make changes as it deems necessary to any products described herein for any reason, including
without limitation enhancement in reliability, functionality or design. No license is granted, whether expressly or by implication, in relation to
the use of any products described herein or to the use of any information provided herein, under any patent or other intellectual property rights of
Silicon Standard Corporation or any third parties.
01/31/2008 Rev.1.00
www.SiliconStandard.com
20