High Frequency Switch Mode
Li-Ion Battery Charger
ADP3806
FEATURES
Li-Ion Battery Charger
Three Battery Voltage Options
Selectable 12.525 V/16.700 V
Selectable 12.600 V/16.800 V
Adjustable
High End-of-Charge Voltage Accuracy
0.4% @ 25 C
0.6% @ 5 C to 55 C
0.7% @ 0 C to 85 C
Programmable Charge Current with Rail-to-Rail
Sensing
System Current Sense with Reverse Input Protection
Soft-Start Charge Current
Undervoltage Lockout
Bootstrapped Synchronous Drive for External NMOS
Programmable Oscillator Frequency
Oscillator SYNC Pin
Low Current Flag
Trickle Charge
APPLICATIONS
Portable Computers
Fast Chargers
GENERAL DESCRIPTION
The ADP3806 is a complete Li-Ion battery-charging IC. The
device combines high output voltage accuracy with constant
current control to simplify the implementation of constant-
current, constant-voltage (CCCV) chargers. The ADP3806 is
available in three options: The ADP3806-12.6 guarantees the
final battery voltage selected is 12.6 V or 16.8 V
±
0.6%, the
ADP3806-12.5 guarantees 12.525 V/16.7 V
±
0.6%, and the
ADP3806 is adjustable using two external resistors to set the
battery voltage. The current sense amplifier has rail-to-rail inputs
to accurately operate under low dropout and short-circuit condi-
tions. The charge current is programmable with a dc voltage on
ISET. A second differential amplifier senses the system current
across an external sense resistor and outputs a linear voltage
on the ISYS pin. The bootstrapped synchronous driver allows
the use of two NMOS transistors for lower system cost.
FUNCTIONAL BLOCK DIAGRAM
VCC
BST
DRVH SW
DRVL
PGND
CS+
CS–
SYS+ SYS–
ISYS
BOOTSTRAPPED
SYNCHRONOUS
DRIVER
SD
VREF + VREG
UVLO
BIAS
VREF
IN DRVLSD DRVLSD
+
V
TH
–
+
–
AMP1
–
+
AMP2
–
LIMIT
2.5V
+
BSTREG
–
+
–
SD
LOGIC
CONTROL
–
gm2
+
VREF
SELECT
12.6/16.8
LC
OSCILLATOR
ADP3806
AGND
REG
REF
SYNC
CT
REV. B
Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties that
may result from its use. No license is granted by implication or otherwise
under any patent or patent rights of Analog Devices. Trademarks and
registered trademarks are the property of their respective owners.
+
–
gm1
+
ISET
BAT
COMP
BATSEL
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
www.analog.com
Fax: 781/326-8703
© 2004 Analog Devices, Inc. All rights reserved.
ADP3806–SPECIFICATIONS
Parameter
BATTERY SENSE INPUT
ADP3806-12.6 V and 16.8 V
ADP3806-12.525 V and 16.7 V
Conditions
1
(@ 0 C
£
T
A
£
100 C, VCC = 16 V, unless otherwise noted.)
Symbol
Min
Typ
Max
Unit
Input Resistance
Input Current
BATTERY SENSE INPUT
ADP3806
V
BAT
= 2.5 V
Input Current Operating
Input Current Shutdown
OSCILLATOR
Maximum Frequency
2
Frequency Variation
3
CT Charge Current
0% Duty Cycle Threshold
Maximum Duty Cycle Threshold
SYNC Input High
SYNC Input Low
SYNC Input Current
GATE DRIVE
On Resistance
Rise, Fall Time
Overlap Protection Delay
SW Bias Current
BST Cap Refresh Threshold
CURRENT SENSE AMPLIFIER
Input Common-Mode Range
Input Differential Mode Range
Input Offset Voltage
5
Gain
5
Input Bias Current
Input Offset Current
Input Bias Current
DRVL Shutdown Threshold
SYSTEM CURRENT SENSE
6
Input Common-Mode Range
Input Differential Range
Input Offset Voltage
Input Bias Current, SYS+
Input Bias Current, SYS–
Voltage Gain
Output Range
Limit Output Threshold
Limit Output Voltage
ISET INPUT
Charge Current Programming
Function
Programming Function Accuracy
T
A
= 25∞C, 13 V
£
VCC
£
20 V
5∞C
£
T
A
£
55∞C
0∞C
£
T
A
£
85∞C
Part in Operation
Part in Shutdown
V
BAT
V
BAT
V
BAT
R
BAT
I
BAT(SD)
–0.4
–0.6
–0.7
250
+0.4
+0.6
+0.7
350
0.2
1.0
%
%
%
kW
mA
T
A
= 25∞C, 13 V
£
VCC
£
20 V
V
BAT
V
BAT
0∞C
£
T
A
£
85∞C
BATSEL = Open, Part in Operation
BATSEL = 100 kW to GND, Part in Shutdown
f
CT
f
CT
I
CT
–0.5
–0.7
0.2
0.2
1000
210
125
+0.5
+0.7
1.0
1.0
%
%
mA
mA
kHz
kHz
mA
V
V
V
V
mA
W
ns
ns
mA
V
V
mV
mV
V/V
mA
mA
mA
mV
V
mV
mV
mA
mA
V/V
V
V
V
CT = 180 pF
@ COMP Pin
@ COMP Pin
250
150
1.0
2.5
290
175
SYNC
H
SYNC
L
I
SYNC
I
L
= 10 mA
C
L
= 1 nF, DRVL and DRVH
DRVL Falling to DRVH Rising,
DRVH Falling to DRVL Rising
Part in Shutdown, V
SW
= 12.6 V
V
BST
– V
SW
V
CS+
and V
CS–
V
CS4
0 V
£
V
CS(CM)
£
VCC
0 V
£
V
CS(CM)
£
VCC, Part in Operation
0 V
£
V
CS(CM)
£
VCC
Part in Shutdown
Measured between V
CS+
and V
CS–
SYS+ and SYS–, I
L
= 0 mA, V
ISYS
= 3 V
(V
SYS+
) – (V
SYS–
)
V
SYS(DM)
= 0 V, V
SYS(CM)
= 16 V
V
SYS(DM)
= 0 V, V
SYS(CM)
= 16 V
10 V
£
V
SYS(CM)
£
VCC + 0.3 V, I
L
= 100
mA
I
L
= 1 mA
7
, V
SYS(CM)
> 6 V
V
LIMIT
£
0.2 V, 50 kW Pull-up to 5 V
V
ISYS
> 2.65 V, I
SINK
= 700
mA
R
ON
t
r
, t
f
t
OP
2.2
0.2
6
35
50
0.2
3.7
0.8
1.0
10
1.0
V
CS(CM)
V
CS(DM)
V
CS(VOS)
V
CS(IB)
V
CS(IOS)
V
CS(SD
)
V
SYS(CM)
V
SYS(DM)
I
B(SYS+)
I
B(SYS–)
V
ISYS
V
TH(LIMIT)
V
O(LIMIT)
0.0
0.0
1.0
25
50
1.0
0.2
48
4.0
0
0.5
200
70
50
2.5
0.1
VCC + 0.3
160
100
2.0
1.0
VCC + 0.3
100
300
125
51.5
5.0
2.7
0.2
48.5
0
2.3
ISET Bias Current
0.0 V < V
ISET
£
4.0 V
V
ISET
= 4.0 V, 1 V
£
V
CS(CM)
£
16 V
V
ISET
= 0.50 V, 1 V
£
V
CS(CM)
£
10 V
5∞C
£
T
A
£
55∞C, V
ISET
= 206 mV,
V
CS(CM)
= 5 V and 10 V
0.0 V
£
V
ISET
£
4.0 V
V
ISET/VCS
–5
–30
–46.7
I
B
25
±
1.0
±
10
+5
+30
+33
1.0
V/V
%
%
%
mA
0.2
–2–
REV. B
ADP3806
Parameter
BATSEL INPUT
V
BAT
= 12.6 V
V
BAT
= 16.8 V
BATSEL Input Current
BOOST REGULATOR OUTPUT
Output Voltage
Output Current
8
ANALOG REGULATOR OUTPUT
Output Voltage
Output Current
8
PRECISION REFERENCE OUTPUT
Output Voltage
Output Current
8
SHUTDOWN (SD)
ON
OFF
SD
Input Current
POWER SUPPLY
ON Supply Current
OFF Supply Current
UVLO Threshold Voltage
UVLO Hysteresis
LC OUTPUT
Output Voltage Low
Output Voltage High
OUTPUT REVERSE LEAKAGE
PROTECTION
Leakage Current
OVERCURRENT COMPARATOR
Overcurrent Threshold
Response Time
OVERVOLTAGE COMPARATOR
Overvoltage Threshold
Response Time
No External Loads, UVLO
£
VCC
£
20 V
No External Loads, VCC
£
20 V
Turn On
Turn Off
High Current Mode
9
, I
SINK
= 100
mA
Low Current Mode
10
C
L
= 0.1
mF
V
BSTREG
I
BSTREG
V
REG
I
REG
V
REF
I
REF
SD
H
SD
L
Conditions
Symbol
Min
2.0
0.2
6.8
3.0
5.8
3.0
2.47
0.5
2.0
0.2
I
SYON
I
SYOFF
V
UVLO
6.0
1.0
6.0
0.3
0.8
1.0
8.0
5.0
6.25
0.5
7.0
5.0
6.0
5.0
2.5
1.1
0.8
5.0
7.2
Typ
Max
Unit
V
V
mA
V
mA
V
mA
V
mA
V
V
mA
mA
mA
V
V
V
V
C
L
= 10 nF
6.2
2.53
5.65
0.1
0.1
0.4
External
VCC = Floating, V
BAT
= 12.6 V
I
DISCH
V
CS(OC)
t
OC
V
BAT(OV)
t
OV
1
180
2
120
2
5
mA
mV
ms
%
ms
V
CS
> 180 mV to COMP < 1 V
V
BAT
> 120% to COMP < 1 V
NOTES
1
All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods.
2
Guaranteed by design, not tested in production.
3
If SYNC function is used, then f
SYNC
must be greater than f
CT
but less than 120% of f
CT
.
4
V
CS
= (V
CS+
) – (V
CS–
).
5
Accuracy guaranteed by ISET input, programming function accuracy specification.
6
System current sense is active during shutdown.
7
Load current is supplied through SYS+ pin.
8
Guaranteed output current from 0 to min specified value to maintain regulation.
9
V
BAT
< 93% of final or V
CS
> 25 mV.
10
V
BAT
≥
93% of final and V
CS
£
25 mV.
Specifications subject to change without notice.
REV. B
–3–
ADP3806
ABSOLUTE MAXIMUM RATINGS*
Input Voltage (VCC) . . . . . . . . . . . . . . . . . . . –0.3 V to +25 V
BAT, CS+, CS– . . . . . . . . . . . . . . . . . –0.3 V to VCC + 0.3 V
SYS+, SYS– . . . . . . . . . . . . . . . . . . . . . . . . . . –25 V to +25 V
BST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +30 V
BST to SW . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +8 V
SW to PGND . . . . . . . . . . . . . . . . . . . . . . . . . . –4 V to +25 V
DRVL to PGND . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +8 V
ISET, BATSEL,
SD,
SYNC, CT,
LIMIT, ISYS, LC . . . . . . . . . . . . . . . . . . . –0.3 V to +10 V
COMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +3 V
GND to PGND . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +0.3 V
Operating Ambient Temperature Range . . . . . . 0∞C to 100∞C
JA
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115∞C/W
Operating Junction Temperature Range . . . . . . 0∞C to 125∞C
Storage Temperature Range . . . . . . . . . . . . –65∞C to +150∞C
Lead Temperature Range (Soldering 10 sec) . . . . . . . . . 300∞C
*Stresses
above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational
sections of this specification is not implied. Exposure to absolute maximum rating
conditions for extended periods may affect device reliability. Absolute maximum
ratings apply individually only, not in combination. Unless otherwise specified all
other voltages are referenced to GND.
ORDERING GUIDE
Model
ADP3806JRU-REEL
ADP3806JRU-REEL7
ADP3806JRU-12.5-RL
ADP3806JRUZ-12.5RL
*
ADP3806JRU-12.5-R7
ADP3806JRU-12.6-RL
ADP3806JRU-12.6-R7
*Z
= Pb-free part.
Battery
Voltage
Adjustable
Adjustable
12.525 V/16.7 V
12.525 V/16.7 V
12.525 V/16.7 V
12.600 V/16.8 V
12.600 V/16.8 V
Package
Description
TSSOP-24
TSSOP-24
TSSOP-24
TSSOP-24
TSSOP-24
TSSOP-24
TSSOP-24
Package
Option
RU-24
RU-24
RU-24
RU-24
RU-24
RU-24
RU-24
Quantity
per Reel
2500
1000
2500
2500
1000
2500
1000
CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily
accumulate on the human body and test equipment and can discharge without detection. Although the
ADP3806 features proprietary ESD protection circuitry, permanent damage may occur on devices
subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended
to avoid performance degradation or loss of functionality.
–4–
REV. B
ADP3806
PIN CONFIGURATION
VCC
1
SYS–
2
SYS+
3
ISYS
LIMIT
4
5
24
23
22
21
PIN FUNCTION DESCRIPTION(continued)
Pin No. Mnemonic Function
SW
DRVH
BST
BSTREG
DRVL
9
10
11
12
13
14
REF
SD
COMP
LC
AGND
BAT
2.5 V Precision Reference Output.
Shutdown Control Input.
External Compensation Node.
Low Current Output.
Analog Ground.
Battery Sense Input.
2.5 V for ADP3806.
12.525 V/16.7 V for ADP3806-12.5.
12.6 V/16.8 V for ADP3806-12.6.
Battery Voltage Sense Input.
High = 3 Cells, Low = 4 Cells.
Charge Current Program Input.
Negative Current Sense Input.
Positive Current Sense Input.
Power Ground.
Low Drive Output Switches between
REG and PGND.
7.0 V Regulator Output for Boost.
Floating Bootstrap Supply for DRVH.
High Drive Output Switches between
SW and BST.
Buck Switching Node Reference for
DRVH.
ADP3806
20
TOP VIEW
19
PGND
(Not to Scale)
18
CS+
SYNC
7
REG
8
REF
9
17
16
15
14
13
CT
6
CS–
ISET
BATSEL
BAT
AGND
SD
10
COMP
11
LC
12
15
16
PIN FUNCTION DESCRIPTION
BATSEL
ISET
CS–
CS+
PGND
DRVL
BSTREG
BST
DRVH
SW
17
18
19
20
21
22
23
24
Pin No. Mnemonic Function
1
2
3
4
5
6
7
8
VCC
SYS–
SYS+
ISYS
LIMIT
CT
SYNC
REG
Supply Voltage.
Negative System Current Sense Input.
Positive System Current Sense Input.
System Current Sense Output.
System Current Sense Limit Output.
Oscillator Timing Capacitor.
Oscillator Synchronization Pin.
6.0 V Analog Regulator Output.
REV. B
–5–