ACTIVE-SEMI ACT2802 5v/2.5a backup battery pack manager Datasheet

ACT2802
Rev 0, 21-Jan-14
5V/2.5A Backup Battery Pack Manager
FEATURES
 Dedicated Single Chip Solution for Mobile

APPLICATIONS
Power With Minimal Component Count
5V/2.5A Constant Output Current Limit in
Boost Mode
2.5A Switching Charger Current Limit
Programmable 4.1V to 4.35V Battery Voltage
95% Boost Efficiency (Vbat=4.1V)







 Adaptive to 10mA-2400mA Input Sources
 Battery Disconnection at Output Short
 <10µA Low Battery Leakage Current at HZ













Backup Battery Pack
Power Bank
Mobile Power
Standalone Battery Charger with USB Output
GENERAL DESCRIPTION
ACT2802 is a space-saving and high-performance
low-profile single-chip solution for backup battery
pack and standalone battery charger. ACT2802
integrates all the functions that a backup battery
pack needs, including switching charger, boost
converter and LED indication.
Mode During Storage
Boost Auto Turn-off at No Load and Push
Button Turn-on
Battery Over Current, Over Voltage, Over
Temperature and Short Circuit Protections
Boost Auto Startup with Load Detection
Up to 3.0A Input Current Limit with Prioritized
Power Path to Output
5V+/-100mV Output Voltage in Boost Mode
1.1MHz/0.55MHz Switching Frequencies
2.2uH Inductor and Low Profile Ceramic
Capacitors
4 LEDs Battery Level and Status Indication
Battery Impedance Compensation
Full Cycle of Battery Charge Management
Preconditioning, Fast Charge, Top off and End
of Charge
Charge Current Foldback at 110°C Die
Temperature
IC Over Temperature Protection at 160°C
QFN4x4-24 Package
ACT2802 operates at 1.1MHz for switching charger
and 0.55MHz for boost converter allowing tiny
external inductor and capacitors. ACT2802 provides
a direct power path from input to output with
programmable current limit while providing power
to switching charger. Output has higher priority than
battery charger if the programmed input current limit
is reached.
ACT2802 charges battery with full cycle of
preconditioning, fast charge with constant current
and constant voltage until end of charge. The
battery charger is thermally regulated at 110°C with
charge current foldback.
ACT2802 boost converter steps battery voltage up
to 5V. Boost converter features high efficiency,
constant current regulation, short circuit protection
and over voltage protection.
ACT2802 provides 3.5mA constant currents to drive
4 LEDs to indicate battery level and charge status.
Boost Output Voltage (V)
Boost CC/CV Profile
5.5
VBAT =3.2V
5.0
VBAT =3.7V
4.5
4.0
VBAT =4.1V
3.5
3.0
0
0.3
0.6
0.9
1.2
1.5
1.8
2.1
2.4
2.7
Output Current (A)
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ACT2802
Rev 0, 21-Jan-14
ORDERING INFORMATION
PART NUMBER
BOOST SWITCH
FREQUENCY
OUTPUT
CHARGE
CURRENT
PACKAGE
PACKING
ACT2802QL-T
0.55MHz
5V/2.5A
2.5A
QFN44-24
TAPE & REEL,
3KU/REEL
PIN CONFIGURATION
TOP VIEW
24
23
22
21
20
19
HZ
PB
1
18
2
17
AGND
nPG
ILIM
VIN
3
16
4
15
5
14
EP
6
7
8
9
10
13
11
LED1
BTV
ICST
IOST
CSN
CSP
12
QFN44-24
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ACT2802
Rev 0, 21-Jan-14
PIN DESCRIPTIONS
PIN
NAME
DESCRIPTION
1
HZ
Boost/high-Z mode enable pin, internally pulled up by a 3MΩ resistor to battery. When
HZ pin is pulled ground, boost is enabled if VIN is not present.
2
PB
Push button input, connect a push button from this pin to AGND, internally pulled up
by a 3MΩ resistor to battery. When this pin is pushed for 100ms, LED1-4 indicators
are enable for 5 seconds. PB starts up boost converter if HZ pin is grounded and VIN
is not present.
3
AGND
4
nPG
Drive external P-FET to protect output short circuit and leakage during shutdown. nPG
pin is pulled up to VOUT internally. nPG pin is pulled low if VOUT is in the range.
5
ILIM
Input current limit setting pin. Connect a resistor from this pin to AGND to set the input
current limit. The current setting ranges from 1.0A-3.0A.
6
VIN
USB or AC adaptor input. When VIN is valid, charge and power path is enabled.
7, 8
VOUT
9, 10
SW
11
PGND
Power ground. PGND is connected to the source of low-side N-channel MOSFET and
the MOSFET’s gate driver.
12
BAT
Battery input. Connected to the battery pack positive terminal to provide power in High
-Z mode. Bypass to PGND with a high quality ceramic capacitor placed as close to the
IC as possible.
13
CSP
Positive terminal of charge current sense input. Kevin sense is required with 10nF
ceramic capacitor right across CSP and CSN pins.
14
CSN
Negative terminal of charge current sense input.
15
IOST
Output current setting. Connect a resistor from this pin to AGND to set output constant
current. The current setting ranges from 1.0A-2.5A.
16
ICST
Fast charge current setting pin. Connect a resistor from this pin to AGND to set the
charge current. The current setting ranges from 1.0A-2.5A.
17
BTV
Battery termination voltage setting. Connect a resistor from this pin to AGND to
program battery charge termination voltage.
18
LED1
Battery level indicator. An internal 3.5mA sink current limit is built in.
19
LED2
Battery level indicator. An internal 3.5mA sink current limit is built in.
20
LED3
Battery level indicator. An internal 3.5mA sink current limit is built in.
21
LED4
Battery level indicator. An internal 3.5mA sink current limit is built in.
22
RIMC
Battery impendence compensation input. Connect to a resistor from this pin to APNG
to program the battery impedance.
23
BLVS
Battery level voltage shift. Connect a resistor from this pin to AGND to shift the battery
LED indication thresholds.
24
TH
Temperature sensing input. Connect to battery thermistor terminal. If no use, put 10K
pulled down resistor.
25
EP
Exposed pad. Must be soldered to ground on the PCB.
Logic Ground.
Output pin. Bypass to PGND with a high quality low ESR and ESL ceramic capacitor
placed as close to the IC as possible.
Internal switch to output inductor terminal.
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ACT2802
Rev 0, 21-Jan-14
ABSOLUTE MAXIMUM RATINGS
PARAMETER
VALUE
UNIT
-0.3 to 6.5
V
Junction to Ambient Thermal Resistance
40
°C/W
Maximum Power Dissipation
2.5
W
Operating Ambient Temperature
-40 to 85
°C
Operating Junction Temperature
-40 to 150
°C
Storage Junction Temperature
-40 to 150
°C
300
°C
All the Pin to PGND and AGND
Lead Temperature (Soldering 10 sec.)
: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may
affect device reliability.
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ACT2802
Rev 0, 21-Jan-14
ELECTRICAL CHARACTERISTICS
(VIN = 5V, TA = 25°C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX UNIT
Input Current Limit
Input Voltage Range
4.5
VIN Over Voltage Protection
VIN rising, VIN_OVP
Input Voltage Validation Time
VIN_UVLO<VIN<VIN_OVP
Input Current Limit Setting Range
RILIM=0.806kΩ—2.4kΩ
Input Current Limit
RILIM=0.806kΩ
5.5
6.0
5.5
V
6.5
V
32
1.0
ms
3.0
3.0
Input Current Limit Gain
A
A
2000
Leakage Current from VOUT to VIN in Boost
Mode
3.0V<VBAT<4.35V, Ta=25℃
0
10
µA
Battery Discharge Current in High-Z Mode
3.0V<VBAT<4.35V, Ta=25℃
7.5
15
µA
Power Switches
VIN-to-VOUT FET on Resistance
80
mΩ
VOUT-to-SW FET on Resistance
60
mΩ
SW-to-PGND FET on Resistance
65
mΩ
Buck Converter
Switching Frequency
ACT2802QL-T
High Side Switch Peak Current Limit
-15%
1.1
4.5
6
A
100
ns
Minimum On-time
+15%
MHz
Over Temperature Protection (OTP)
OTP rising
160
℃
OTP Hysteresis
OTP falling
35
℃
Charge Mode
Charge Current Setting Range
Rcs=25mΩ, RICST=20kΩ—50kΩ
Charge Current Setting (ICHRG)
Rcs=25mΩ, RICST=43.2kΩ
1.0
Thermal Regulation Temperature
Battery Adjust Voltage(VBAJ)
Rbtv=25kΩ
End of Charge (EOC) Voltage
-0.5%
2.5
A
2.1
A
110
℃
0.1
V
4.1+VBAJ 0.5%
V
EOC Voltage Accuracy
Rbtv=0
4.1
V
Battery Over Voltage Threshold
VBAT rising
4.6
V
Battery Over Voltage Threshold Hysteresis
VBAT falling
200
mV
Fast Charge Current
VBAT=3.5V
ICHRG
A
Precondition Charge Current
2.4V≤VBAT≤2.8V, Percent of ICHRG
10
%
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ACT2802
Rev 0, 21-Jan-14
ELECTRICAL CHARACTERISTICS
(VIN = 5V, TA = 25°C, unless otherwise specified.)
PARAMETER
Precondition Voltage Threshold
TEST CONDITIONS
MIN
VBAT rising, Rbtv=0
Precondition Voltage Threshold Hysteresis
TYP
MAX UNIT
2.8
V
130
mV
Low VBAT Charge Current
VBAT=1V, RICST=43.2kΩ
200
mA
EOC Current Threshold
VBAT=4.2V, percent of the fast
charge current
13
%
200
mV
Charge Restart Voltage Threshold
TH Upper Temperature Voltage Threshold
Cold detect NTC thermistor
1.45
1.5
1.55
V
TH Lower Temperature Voltage Threshold
Hot detect NTC thermistor
0.28
0.3
0.32
V
TH Hysteresis
50
mV
TH Internal Pull-up Current
60
µA
Charge Current Foldback
Charge Current Reduction Threshold1 of Vout1
Starting foldback point
Charge Current Reduction Threshold2 of Vout1
Stop foldback point, RCS=25mΩ,
RICST=43.2kΩ
4.63
4.7
4.77
4.57
V
V
Boost Mode
Input Voltage Operation Range
3.0
-15%
0.55
4.5
V
+15%
MHz
Switching Frequency
ACT2802QL-T
Input Voltage UVLO
VBAT rising
3.3
V
Input Voltage UVLO Hysteresis
VBAT falling
400
mV
Output Voltage
Ta=25℃
Output Voltage Accuracy
All conditions
4.97
5.05
5.10
V
-3
VOUT
2
%
80mA-1A-80mA, 0.1A/us
4.75
5.25
V
1A-2.0A-1A, 0.1A/us
4.7
5.25
V
Output Voltage Transient Response
Output Over Voltage Protection
VOUT rising
5.7
V
Output Over Voltage Protection Hysteresis
VOUT falling
300
mV
Output Current Regulation Range
Rcs=25mΩ, RIOST=37.4kΩ—93.7kΩ
Output Current Limit
Rcs=25mΩ, RIOST=91kΩ
1.0
Minimum On-Time
Low Side Switch Peak Current Limit
VBAT=3.6V, VOUT=5V
Soft-Startup Time
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4.9
2.5
A
2.4
A
100
ns
6.9
A
400
µs
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Copyright © 2013 Active-Semi, Inc.
ACT2802
Rev 0, 21-Jan-14
ELECTRICAL CHARACTERISTICS
(VIN = 5V, TA = 25°C, unless otherwise specified.)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX UNIT
Under Voltage Protection (UVP Threshold)
VOUT falling
4.25
V
Under Voltage Protection (UVP Threshold)
VOUT rising
4.6
V
3
ms
UVP Blanking Time During Startup
UVP Sense Detection Time
VOUT falling
20
µs
Restart After UVP
Hiccup mode
2
s
Light Load Current Shut off Threshold
40
mA
Light Load Current Detect Time
90
s
HZ Pin High Voltage
HZ voltage rising
HZ Pin Low Voltage
HZ voltage falling
0.9
0.4
1.4
V
0.75
V
HZ Internal Pull-up Resistor
3
MΩ
PB Turn off Boost Time
3
s
PB Turn on Boost Time
100
ms
2
s
Mode Transition
Transition Waiting Time between Charge
Mode and Boost Mode
TRANTIME
Battery Level Indication
Battery Impedance Compensation Range
Battery Impedance Compensation
40
Rcs=25mΩ, RIMC=200kΩ
PB Deglitch Time
PB High Input Voltage
PB voltage rising
PB Low Input Voltage
PB voltage falling
PB Internal Pull-up Resistor
LED Indication Time
PB is pushed and released
LED Flash Frequency
Charging, LED flash 1s on and 1s off
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500
200
mΩ
100
ms
0.9
0.4
mΩ
1.4
V
0.75
V
3
MΩ
5
s
0.5
Hz
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ACT2802
Rev 0, 21-Jan-14
FUNCTIONAL BLOCK DIAGRAM
FUNCTIONAL DESCRIPTION
at VOUT, and the current limit switch Q1 is turned
off, and the reverse current from VOUT to VIN is
blocked. In HZ mode, all the switches are turned off
and the drainage current from battery is very low.
The system operation flow chart as shown in Figure
1.
ACT2802 is a complete battery charging and
discharging power management solution for
applications of single-cell lithium-based backup
battery pack or power bank. There is a power path
from input to output with programmable input
current limit. When output is over loaded, the input
switch Q1 starts going into linear mode and thus
output voltage starts to drop. If output voltage drops
below 4.25V, the input switch Q1 turns off and
restart in 2 seconds.
Any transitions between boost mode and charge
mode go through HZ mode by turning off all the
switches Q1-Q3 into HZ mode for 2 seconds before
enabling the other mode.
With the advanced ACT2802 architecture, a
synchronous buck/boost converter is connected
from VOUT to switching node (SW). With the
bidirectional architecture, the converter could be
configured as either buck to charge battery or boost
to discharge battery. With switching charger and
discharger, the higher charge current and higher
conversion efficiency are achieved.
The modes are determined by HZ pin and VIN pin
as shown in the table 1. A valid VIN voltage forces
ACT2802 into charge mode. Boost mode is enabled
if HZ pin is pulled low and VIN is invalid or not
present. When HZ=0, if PB is pulled low for more
than 100ms, boost converter is enabled. A running
boost is disabled if one of the following conditions is
met:
Modes of Operation
1. After PB is released, if PB is pulled low for more
than 3 seconds.
ACT2802 has 3 operation modes: charge mode,
boost mode and high-impedance (HZ) mode. In
charge mode, the input current limit is enabled and
the Q2 and Q3 operate as a buck converter to
charge battery. In boost mode, Q2 and Q3 operate
as boost converter to step battery voltage up to +5V
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2. Boost converter output current is below light
load threshold for 1.5 minutes.
3. Battery voltage falls below the boost cut-off
threshold.
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ACT2802
Rev 0, 21-Jan-14
FUNCTIONAL DESCRIPTION
Figure 1:
ACT2802 System Operation Flow Chart
to decrease as necessary to maintain charging at
the termination voltage.
Table 1: Mode Selection
HZ PIN
0
0
1
1
VIN Valid
0
1
0
1
Mode
Boost
Charge
HZ
Charge
Precondition Charge
A new charging cycle begins with the precondition
state, and operation continues in this state until VBAT
exceeds the precondition threshold voltage. When
operating in precondition state, the cell is charged
at a reduced current, 10% of the programmed
maximum fast charge constant current. Once VBAT
reaches the precondition threshold voltage the state
machine jumps to the fast charge state.
Input Current Limit
When the input current reaches the programmed
value, switch Q1 goes into linear mode and output
voltage starts to drop. When output voltage drops to
4.25V, hiccup mode is triggered and switch Q1
turns off and restart in 2 seconds.
Fast Charge
Switching Battery Charger
If battery voltage is above preconditioning
threshold, buck converter charges battery with
constant current. In fast charge state, the ACT2802
charges at the current set by the external resistor
connected at the ICST pin. During a normal charge
cycle fast charge continues in CC mode until VBAT
reaches the charge termination voltage, at which
point the ACT2802 charges in top off state.
ACT2802 is configured in charge mode (buck
mode) when VIN is valid. In this mode, a battery is
charged with preconditioning, fast charge, top-off
and end of charge (EOC). The typical charge
management is shown in Figure 2 and Figure 3.
CC/CV Regulation Loop
There are CC/CV regulation loops built in ACT2802,
which regulates either current or voltage as
necessary to ensure fast and safe charging of the
battery. In a normal charge cycle, this loop
regulates the current to the value set by the
external resistor at the ICST pin. Charging
continues at this current until the battery cell voltage
reaches the termination voltage. At this point the
CV loop takes over, and charge current is allowed
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Top Off
With the battery voltage approaches the EOC
voltage set by the BTV pin. Charge current
decreases as charging continues. In the top off
state, the cell is charged in constant voltage (CV)
mode. During a normal charging cycle charging
proceeds until the charge current decreases below
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ACT2802
Rev 0, 21-Jan-14
FUNCTIONAL DESCRIPTION
the end of charge (EOC) threshold, defined as 13%
of fast charge current. When this happens, the state
machine terminates the charge cycle and jumps to
the EOC state.
charge mode and keep monitoring the battery
voltage.
End of Charge
When battery voltage drops by 200mV below the
end of charge voltage, the charger is reinitiated
with constant current charge.
When charges current decreases to 13% of set fast
charge current, the buck converter goes into end of
Recharge
Figure 2.
Typical Li+ Charge Profile and ACT2802 Charge States
A: PRECONDITION STATE
B: FAST-CHARGE STATE
C: TOP-OFF STATE
D: END-OF-CHARGE STATE
Figure 3.
Charger State Diagram
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ACT2802
Rev 0, 21-Jan-14
programmed by a resistor connected from BLVS
pin to AGND as shown in Figure 5. The following
equation shows the LED4 voltage threshold:
APPLICATIONS INFORMATION
Battery Charge Termination Voltage
Battery charge termination voltage is set by a
resistor Rbtv connected from BTV pin to AGND as
shown in Figure 4. The battery charge termination
voltage is estimated as the following equation:
V BAT (V )  4 .1(V )  Rbtv  4  10 6 (V )
VBATLED4 (V )  3.5(V )  0.01(mA)  RBLVS (k)
(2)
(1)
Rbtv is selected based on the battery voltage rating.
1% accuracy resistor is recommended for Rbtv.
Figure 5.
Battery level voltage shift setting circuit
As long as LED4 is set, all the other 3 LED
thresholds is fixed as shown in the table 3:
Table 3: 4 LED Voltage Thresholds
RBLVS (ohm)
50K
60K
70K
80K
LED1
3.35V
3.45V
3.55V
3.65V
LED2
3.60V
3.70V
3.80V
3.90V
LED Status Indication
LED3
3.75V
3.85V
3.95V
4.05V
4 LEDs ON/OFF and flash show the charge status
and the remained capacity level as shown in the
table 2. The LED status is based on battery voltage
and operation modes. In charge mode, when a
battery is fully charged, flashing stops and all the 4
LEDs are solid on.
LED4
4.00V
4.10V
4.20V
4.30V
Figure 4.
Battery terminal voltage setting circuit
Battery level voltage shift (BLVS pin)
LED1-4 voltage thresholds are adjusted from HZ
mode during charging and discharging based on
the compensated impedance. Those thresholds are
Input Current Limit
An external resistor is used to set the input current
limit connected from ILIM pin to AGND as shown in
Figure 6. Input current limit has built-in soft startup
and current foldback control loop. The input current
limit is estimated as the following equation:
I ILIM (A) 
2 .4 (V)
R ILIM (k  )
(3)
Table2: LED Indication
Charge Mode
PB time>100ms (Boost or HZ Mode)
LED1
LED2
LED3
LED4
LED1
LED2
LED3
LED4
VBAT<LED1
Flash
Off
Off
Off
Off
Off
Off
Off
LED1≤VBAT<LED2
On
Flash
Off
Off
On
Off
Off
Off
LED2≤VBAT<LED3
On
On
Flash
Off
On
On
Off
Off
LED3≤VBAT<LED4
On
On
On
Flash
On
On
On
Off
VBAT≥LED4
On
On
On
Flash
On
On
On
On
VBAT≥LED4
(End of Charge)
On
On
On
On
On
On
On
On
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ACT2802
Rev 0, 21-Jan-14
from IOST pin to AGND as shown in Figure 10. The
boost output current is estimated as the following
equation:
I IOST (A) 
Figure 6.
2
R
(k  )
( A )  IOST
3
Rc s (m  )
(5)
Input current limit setting circuit
Input current limit at various resistor curve is shown
in Figure 7.
3.5
Figure 10.
3.0
IILIM (A)
2.5
Boost output current setting circuit
Figure 11 gives out boost output current with
various RIOST.
2.0
1.5
3.0
1.0
0.5
0.6
1.0
1.4
1.8
2.2
2.6
2.5
3.0
2.0
Figure 7.
IOUT (A)
RILIM (kΩ)
Input current limit setting
Battery Fast Charge Current
1.0
0.5
Battery fast charge current is set by a resistor
connected from ICST pin to AGND as shown in
Figure 8. Figure 9 gives out different fast charge
current with various RICST. The battery fast charge
current is estimated as the following equation:
Ic ( A )  1 .25 ( A ) 
1.5
0
0
20
40
60
80
100
RIOST (kΩ)
Figure 11.
Boost output current setting
Battery Impedance Compensation
R ICST ( k )
Rcs ( m  )
(4)
An external resistor is used to set the impedance
from 40mΩ to 500mΩ as shown in Figure 12. RIMC
is corresponding to battery impedance. Higher RIMC
gives higher compensation voltage which is
positively proportional to battery charge/discharge
current.
Select RIMC based on battery impedance:
Figure 8.
R IMC (k  ) 
Battery fast charge current setting circuit
25  R (m  )
R cs (m  )
(6)
VBAT (V )  BAT(V )  I BAT ( A)  R(m) 10-3
3.0
(7)
ICHRG (A)
2.5
2.0
1.5
1.0
0.5
0
0
10
20
30
40
50
60
RICST (kΩ)
Figure 9.
Figure 12.
Battery fast charge current setting
Boost Output Constant Current
Boost output current is set by a resistor connected
Innovative PowerTM
Battery impedance compensation setting circuit
The battery impedance as shown in the table 4
according to the RIMC and Rcs:
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ACT2802
Rev 0, 21-Jan-14
Table 4: Battery Impedance
RIMC(KΩ)
Battery
Impedance
R(mΩ)
Flashlight Circuit
50
100
200
Rcs=25mΩ
50
100
200
Rcs=50mΩ
100
200
400
Figure 16 shows a circuit with flashlight driver and
control.
Boost Output Plug-in Auto Detection
Figure 13 provides a solution for auto plug-in
detection.
Figure 16.
Flashlight circuit
LEDs on in Boost Mode
LEDs can be always on during boost mode, the
schematic is shown in Figure17.
Figure 13.
Boost output auto detection circuit
Input Over Voltage Surge
In the case of pure ceramic input capacitor is
chosen, if the input cable is long, stray inductance
may cause over voltage spikes as twice as the
steady-state voltage when input source is plugged
in. Below input circuit is recommended to avoid
input voltage surge. R1 resistor is added in series
with capacitor C1 to damp the potential LC
resonance as shown in Figure 14.
Figure 17.
LEDs on in boost mode circuit
Inductor and Capacitor Selection
ACT2802 supports SMD components. 2.2uH
inductor is recommended. Input side, 4.7uF ceramic
capacitor in series with 2.7Ω resistor are
recommended, on battery side, 22uF ceramic
capacitors is recommended while on output side,
22uFx2 ceramic capacitors are recommended.
Figure 14.
Battery Temperature Monitoring
Input over voltage surge protection circuit
External Input Over Voltage Protection
Considering the maximum voltage rating at VIN pin,
the external OVP circuit as shown in Figure 15 is
recommended if input voltage may go higher than
7V. With the enhanced OVP circuit, input voltage
can be up to 18V.
Figure 15.
In a typical application, the TH pin is connected to
the battery pack's thermistor input as shown in
Figure 18. The ACT2802 injects a 60µA current out of
the TH pin into the thermistor, so that the thermistor
resistance is monitored by comparing the voltage at
TH to the internal VTHL and VTHH thresholds of 0.3V
and 1.5V, respectively. When VTH > VTHH or VTH < VTHL
charging and the charge timers are suspended. When
VTH returns to the normal range, charging and the
charge timers resume.
The net resistance from TH to GND required to cross
Input over voltage protection
Innovative PowerTM
The ACT2802 continuously monitors the
temperature of the battery pack by sensing the
resistance of its thermistor, and suspends charging
if the temperature of the battery pack exceeds the
safety limits.
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ACT2802
Rev 0, 21-Jan-14
the threshold is given by:
60µA×RNOM×kHOT=0.3V→ RNOM×kHOT=5kΩ
60µA×RNOM×kCOLD=1.5V → RNOM×kCOLD= 25kΩ
where RNOM is the nominal thermistor resistance at
room temperature, and kHOT and kCOLD are the ratios
of the thermistor's resistance at the desired hot and
cold thresholds, respectively.
Figure 18.
Battery thermal circuit
Innovative PowerTM
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ACT2802
Rev 0, 21-Jan-14
PC Board Layout Guidance
When laying out the printed circuit board, the
following checklist should be used to ensure proper
operation of the IC.
1. Arrange the power components to reduce the
AC loop size, VIN pin, Vout pin, SW pin and the
schottky diode.
2. Place input decoupling ceramic capacitor C3
and R10 as close to VIN pin as possible.
Resistor R10 is added in series with capacitor
C3 to damp the potential LC resonance .
3. Use copper plane for power GND for best heat
dissipation and noise immunity.
4. Place CSP and CSN capacitor C6 (10nF) close
to CSP and CSN pin as possible, use Kevin
Sense from sense resistor R2 and R2A to CSP
and CSN pins. 22uF decoupling capacitor is
added close to BAT pin.
5. Place the ceramic capacitor C2 and D1 as
close to VOUT and PGND as possible, SW
goes under the C2 (recommend C2 to use 1206
size). SW pad is a noisy node switching. It
should be isolated away from the rest of circuit
for good EMI and low noise operation.
6. Thermal pad is connected to GND layer through
vias (recommend 4X4 pins and the aperture is
10mil). Ground plane, PGND and AGND is
single point connected under the ACT2802
thermal pad through vias to limited SW area.
7. From BAT pin to the Battery positive terminal,
need to lay the divided line to ensure the
battery voltage accuracy of sampling.
8. RC snubber is recommended to add across SW
to PGND to reduce EMI noise. 1A /20V schottky
is added to across VOUT and SW pins.
A demo board PCB layout example is shown in the
figure 19.
Figure 19.
PCB Layout
Bottom Layer
Top Layer
Innovative PowerTM
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ACT2802
Rev 0, 21-Jan-14
BLVS
RIMC
LED4
LED3
LED2
VOUT
SW
SW
PGND
BAT
TH
VOUT
LED1
LED2
LED3
LED4
R8
R7
R6
Figure 20 Typical application circuit
(Input current limit 3.0A, fast charge current limit 2.1A, boost output constant current limit 2.4A)
Innovative PowerTM
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ACT2802
Rev 0, 21-Jan-14
BOM List
ITEM
REFERENCE
DESCRIPTION
QTY
MANUFACTURER
1
L1
Core 6.5*3*3 Dip 2.2uH 6A
1
Sunlord
2
Q1
AO4503, Rdson=19mΩ at VGS = - 4.5 V
1
Vishay
3
Q3
MMBT3906
1
Vishay
4
D1
SS12, Vf=0.5V, 20V Schottky
1
Panjit
5
D2
1N4148, Vf=0.7V, 75V Schottky
1
Vishay
6
C2,C5,C9
Ceramic capacitor, 22uF/10V, X7R, 1206
3
Murata/TDK
7
C3
Ceramic capacitor, 4.7uF/10V, X7R, 1206
1
Murata/TDK
8
C4
Ceramic capacitor, 0.1uF/10V, X7R, 0603
1
Murata/TDK
9
C6
Ceramic capacitor, 10nF/10V, X7R, 0603
1
Murata/TDK
10
C7
Ceramic capacitor, 2.2nF/10V, X7R, 0603
1
Murata/TDK
11
C8,C11,C12,C13
Ceramic capacitor, 2.2uF/10V, X7R, 0603
4
Murata/TDK
12
R1
Chip Resistor, 806Ω, 1/10W, 1%, 0603
1
Murata/TDK
13
R2,R2A
Chip Resistor, 50mΩ, 1/4W, 1%, 1206
2
Murata/TDK
14
R3
Chip Resistor, 93.1kΩ, 1/10W, 1%, 0603
1
Murata/TDK
15
R4,R17
Chip Resistor, 43.2kΩ, 1/10W, 1%, 0603
2
Murata/TDK
16
R5
Chip Resistor, 25kΩ, 1/10W, 1%, 0603
1
Murata/TDK
17
R6
Chip Resistor, 10kΩ, 1/10W, 5%, 0603
1
Murata/TDK
18
R7
Chip Resistor, 60kΩ, 1/10W, 1%, 0603
1
Murata/TDK
19
R8
Chip Resistor, 100kΩ, 1/10W, 1%, 0603
1
Murata/TDK
20
R9
Chip Resistor, 1Ω, 1/8W, 5%, 0805
1
Murata/TDK
21
R10
Chip Resistor, 2.7Ω, 1/4W, 5%, 1206
1
Murata/TDK
22
R11
Chip Resistor, 200kΩ, 1/10W, 5%, 0603
1
Murata/TDK
23
R12,R13
Chip Resistor, 715kΩ, 1/10W, 5%, 0603
2
Murata/TDK
24
R14,R16
Chip Resistor, 49.9kΩ, 1/10W, 5%, 0603
2
Murata/TDK
25
R15
Chip Resistor, 75kΩ, 1/10W, 1%, 0603
1
Murata/TDK
26
R18,R19
Chip Resistor, 100kΩ, 1/10W, 5%, 0603
2
Murata/TDK
27
R20
Chip Resistor, 2.2Ω, 1/10W, 5%, 0603
1
Murata/TDK
28
LED1,LED2,
LED3,LED4
LED, 0603, Blue
4
LED Manu
29
PB
Push Button Switch
1
Nikkai Omron
30
USB
10.2*14.6*7mm, 4P
1
31
Micro-USB
MICRO USB 5P/F SMTB
1
32
U1
IC, ACT2802, T-QFN 44-24
1
Innovative PowerTM
ACT
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ACT2802
Rev 0, 21-Jan-14
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Schematic as show in Figure 20, Ta = 25°C, unless otherwise specified)
Battery Charge V/I Profile
Charge Current VS. Output Current
2500
Input Current (mA)
2500
2000
Input Current
1500
Charge Current
1000
500
VIN = 5.0V
ICHRG = 2.1A
ACT2802-02
ACT2802-01
VIN = 5.0V
VBAT = 3.5V
Charge Current (mA)
3000
2000
1500
1000
500
0
0
0
500
1000
1500
2000
2500
0
0.5
1.0
1.5
2.0
Output Current (mA)
4.0
4.5
2100
2400
Boost Efficiency
90.0
Vbat=3.2V
Efficiency(%)
91.0
ACT2802-04
VIN = 5.0V
ICHRG = 2.1A
ACT2802-03
Efficiency(%)
3.5
100.0
91.5
90.5
90.0
Vbat=3.7V
80.0
Vbat=4.1V
70.0
60.0
50.0
89.5
89.0
40.0
3.0
3.2
3.4
3.6
3.8
4.0
0
4.2
300
600
900
1200
1500
1800
Vbat (V)
Output Current (mA)
Battery Charge Current VS. Temperature
Boost Leakage VS. Temperature
(HZ Mode)
3000
25.0
2500
20.0
IBAT (mA)
2000
ACT2802-06
VIN = 5.0V
VBAT = 3.5V
ACT2802-05
Battery Charge Current (mA)
3.0
Vbat (V)
Charge Efficiency
92.0
2.5
1500
15.0
Vbat=3.5V
Vbat=4.1V
10.0
1000
5.0
500
0
-20
0
0
20
40
60
80
100
120
140
-20
Temperature (°C)
Innovative PowerTM
0
20
40
60
80
100
120
Temperature (°C)
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ACT2802
Rev 0, 21-Jan-14
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Schematic as show in Figure 20, Ta = 25°C, unless otherwise specified)
Boost Output Voltage VS. Temperature
3000
5.4
Boost Output Voltage (V)
2600
2400
2200
2000
1800
0
20
40
60
80
100
120
5.2
5.1
5.0
4.9
140
-30
0
30
60
90
120
Temperature (°C)
Temperature (°C)
Boost Output Voltage VS. Output Current
Boost Output Constant Current Limit
VS. Vbat
Vbat=3.2V
4.93
Vbat=4.15V
4.89
4.85
0
500
1000
1500
2000
2500
150
2550
ACT2801-010
ACT2802-09
5.01
4.97
Boost Output Constant Current mA)
5.05
Boost Output Voltage (V)
5.3
4.8
-20
2500
2450
2400
2350
2300
2250
3000
3.0
3.2
3.4
3.6
3.8
4.0
Boost Output Current (mA)
Vbat (V)
Boost Standby Current VS. Battery Voltage
Boost Leakage VS. Battery Voltage
(HZ Mode)
4.2
8.0
057
0.53
7.0
Battery Leakage (µA)
0.55
ACT2802-012
ACT2802-011
Standby Current (mA)
VBAT = 3.5V
VOUT = 5.05V
ACT2802-08
VBAT = 3.5V
CV= 4.5V
Rcs=25mΩ(1%)
2800
ACT2802-07
Boost Output Constant Current (mA)
Boost Output Constant Current Limit
VS. Temperature
0.51
0.49
0.47
6.0
5.0
4.0
3.0
2.0
1.0
0
0.45
3.0
3.3
3.6
3.9
4.2
45
0
4.8
2.0
3.0
4.0
5.0
Battery Voltage(V)
Battery Voltage(V)
Innovative PowerTM
1.0
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ACT2802
Rev 0, 21-Jan-14
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Schematic as show in Figure 20, Ta = 25°C, unless otherwise specified)
Boost Load Transient (80mA-1A-80mA)
Boost Load Transient (1A-2.1A-1A)
CH1
ACT2802-014
VBAT
= 4.2V
3.4V
V
BAT =
VOUT
= 5.0V
5.0V
V
OUT =
= 1.3A
2.4A
IIIOST
IOST =
ACT2802-013
VBAT = 3.4V
VOUT = 5.0V
IIOST = 2.4A
CH1
CH2
CH2
CH1: VOUT, 100mV/div
CH2: IOUT, 1A/div
TIME: 1ms/div
CH1: VOUT, 100mV/div
CH2: IOUT, 1A/div
TIME: 1ms/div
SW and Output Waveforms in Boost Mode
CH1
CH1
ACT2802-016
VBAT = 4.1V
VOUT = 5.0V
IOUT = 2.4A
ACT2802-015
3.4V
BAT ==3.4V
VVBAT
5.0V
OUT ==5.0V
VVOUT
I
=
1.0A
OUT
IOUT = 2.4A
SW and Output Waveforms in Boost Mode
CH2
CH2
CH1: VOUT, 20mV/div
CH2: VSW, 2V/div
TIME: 1us/div
CH1: VOUT, 20mV/div
CH2: VSW, 2V/div
TIME: 1us/div
Transition Between Buck Mode
and Boost Mode
VIN = 5.0V
VBAT = 4.1V
VIN = 5.0V
VBAT = 4.1V
VIN
VnPG
ACT2802-017
CH1
CH2
CH3
Vout
CH1: VIN, 5V/div
CH2: VnPG, 5V/div
CH3: vout, 2V/div
TIME: 1s/div
Innovative PowerTM
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ACT2802
Rev 0, 21-Jan-14
PACKAGE OUTLINE
QFN44-24 PACKAGE OUTLINE AND DIMENSIONS
SYMBOL
DIMENSION IN
MILLIMETERS
DIMENSION IN
INCHES
MIN
MAX
MIN
MAX
A
0.700
0.800
0.028
0.031
A1
0.000
0.050
0.000
0.002
A3
0.200 REF
0.008 REF
b
0.180
0.300
0.007
0.012
D
3.850
4.150
0.152
0.163
E
3.850
4.150
0.152
0.163
D2
2.500
2.800
0.098
0.110
E2
2.500
2.800
0.098
0.110
e
L
R
K
0.500 BSC
0.350
0.450
0.200 TYP
0.200
---
0.020 BSC
0.014
0.018
0.008 TYP
0.008
---
Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each
product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use
as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of
the use of any product or circuit described in this datasheet, nor does it convey any patent license.
Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact
[email protected] or visit http://www.active-semi.com.
is a registered trademark of Active-Semi.
Innovative PowerTM
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