Preliminary
RT9501A/B
Advanced Lithium-Ion Linear Battery Charger
General Description
The RT9501 is a single Lithium-Ion or Lithium-Polymer
cell linear battery charger which is designed for compact
and cost-sensitive handheld devices. It combines charge
status indication, charge termination, battery temperature
monitoring, and high accuracy current and voltage
regulation in a MSOP-8 package.
The RT9501 charges the battery in three modes,
precharge, constant current, constant voltage. If the
battery voltage is below the precharge threshold V
O(MIN)
,
the RT9501 precharges the battery with a lower
conditioning current. After precharge, the RT9501 applies
a constant current to the battery. An external sense-
resister sets the charge current. The constant voltage
mode continues until the battery reaches the regulation
voltage.
The battery temperature is continuously measured by an
external thermistor through the TS pin. The RT9501
inhibits charge until the temperature is within the range
defined by users.
Features
For Single Lithium-Ion or Lithium-Polymer Cell
Battery Pack (4.1V or 4.2V)
A Few External Components are Required
Precharge, Constant Current, Constant Voltage
Modes
Battery Temperature Monitor
Charge Status Indication
Automatic Battery Recharge
Charge Termination Detect
Auto Low Power Sleep Mode when VDD Power is
Removed
MSOP-8 Package
Applications
Digital Cameras
PDAs
Cellular Phones
Information Appliance
Pin Configurations
(TOP VIEW)
VDD
TS
STAT
GND
1
2
3
4
8
7
6
5
Ordering Information
RT9501
Package Type
F : MSOP-8
Operating Temperature Range
C : Commercial Standard
P : Pb Free with Commercial Standard
Voltage Version
A : 4.1V
B : 4.2V
BATT
CS
FB/CE
CC
MSOP-8
Marking Information
For marking information, contact our sales representative directly or through a RichTek distributor located in your area,
otherwise visit our website for detail.
DS9501A/B-03P October 2004
1
RT9501A/B
Typical Application Circuit
Preliminary
Q1
D1
V
IN
R4
1k
R
CS
C2
0.1uF
to
1uF
+
Battery
Pack
NTC
5
CC
FB/CE
6
BATT
8
TS
STAT
3
2
R
T1
7
CS
1
VDD
4
GND
C1
0.1uF
GND
R3
2k
R
T2
Figure 1. Application circuit using P-Channel MOSFET
V
IN
R
CS
Q1
C2
0.1uF
to
1uF
+
Battery
Pack
R1
1k
NTC
5
7
1
CC
CS
FB/CE
BATT
TS
STAT
6
8
2
3
R
T1
VDD
4
GND
C1
0.1uF
GND
R3
2k
R
T2
Figure 2. Application circuit using PNP transistor
DS9501A/B-03P October 2004
2
Preliminary
Functional Pin Description
Pin Name
VDD
TS
STAT
GND
CC
FB/CE
CS
BATT
Pin Function
Supply Voltage Input.
Temperature Sense Input. Input from battery temperature monitoring circuit.
RT9501A/B
Charge Status Output. 3-state status indication of charge, charge complete and temperature fault or
disable or sleep mode.
Ground.
Charge Control Output. Current output to drive on external PNP transistor or P-Channel MOSFET
for current and voltage regulation.
External Feedback Input or Charge Enable Function. Input from controller or finely adjust the battery
regulated voltage with external voltage divider.
Current Sense Input. Charge current is sensed according to the voltage drop from supply voltage to
this pin.
Battery Voltage input. Input directly from battery voltage.
Function Block Diagram
BATT
VDD
VDD
-
+
Sleep Mode Detection
CC
Control
FB2
-
+
-
+
CV
Control
CS
V
REF1
FB2
V
REF2
TS1 Trip
-
+
-
+
TS
TS2 Trip
-
+
Precharge
Control
Logic
-
+
Recharge
FB2
V
REF3
FB2
V
REF4
CC
VDD
Internal FB
FB/CE
Feedback
Determination
& Enable Control
FB2
STAT
GND
DS9501A/B-03P October 2004
3
RT9501A/B
Absolute Maximum Ratings
Preliminary
(Note 1)
Supply Voltage ---------------------------------------------------------------------------------------------------------
−0.3V
to
7V
Storage Temperature Range ----------------------------------------------------------------------------------------
−65°C
to 150°C
Power Dissipation, P
D
@ T
A
= 25°C
MSOP8 ------------------------------------------------------------------------------------------------------------------ 300mW
Package Thermal Resistance
MSOP8,
θ
JA
------------------------------------------------------------------------------------------------------------ 80°C/W
Operation Junction Temperature Range --------------------------------------------------------------------------
−40°C
to 125°C
Junction Temperature ------------------------------------------------------------------------------------------------- 150°C
ESD Susceptibility (Note 2)
HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 2kV
MM (Machine Mode) -------------------------------------------------------------------------------------------------- 200V
Recommended Operating Conditions
(Note 3)
Supply Input Voltage -------------------------------------------------------------------------------------------------- 4.5V to 7V
Junction Temperature Range ----------------------------------------------------------------------------------------
−20°C
to 70°C
Electrical Characteristics
(T
A
= 25°C, unless otherwise specification)
Parameter
Operating Current
V
DD
Sleep Current
Input Bias Current @ BATT pin
Input Bias Current @ CS pin
Input Bias Current @ TS pin
Input Bias Current @ FB/CE pin
Input Low Voltage @ CE pin
Input High Voltage @ CE pin
Feedback Voltage @ FB pin
Output Voltage
Current Regulation Threshold
Charge Terminated Current
Detect Threshold
Lower Temperature Threshold
Upper Temperature Threshold
Precharge Threshold
Precharge Current Regulation
Recharge Threshold
Symbol
I
DD(OPE)
I
DD(SLP)
I
BATT
I
CS
I
TS
I
CE
V
CE
V
CE
V
FB
Test Condition
4.5V < V
DD
< 7V,
Excluding external loads
V
BATT
−V
DD
≥
0.2V
V
BATT
= V
O(REG)
,
V
BATT
−
V
DD
≥
0.2V
V
CS
=5V, V
BATT
−
V
DD
≥
0.2V
V
TS
=5V, V
BATT
−
V
DD
≥
0.2V
V
CE
=5V, V
BATT
−
V
DD
≥
0.2V
Min
--
--
--
--
--
--
--
V
DD
–1.5
2.048
Typ
1
--
1.5
--
--
--
--
--
2.10
4.10
4.20
110
12
30
60
2.9
14
Max
2
1
2.5
1
1
1
1.5
--
2.152
4.141
4.242
121
22
30.9
61.8
3.0
24
Units
mA
µA
µA
µA
µA
µA
V
V
V
V
V
mV
mV
%V
DD
%V
DD
V
mV
RT9501A
V
O(REG)
V
I(SNS)
V
(TERM)
V
TS1
V
TS2
V
O(MIN)
V
(PRE)
V
O(RCH)
RT9501B
V
I(SNS)
= V
DD
– V
CS
4.059
4.158
100
2
29.1
58.3
2.8
4
V
O(REG)
– V
O(REG)
– V
O(REG)
– V
140mV 100mV
60mV
To be continued
DS9501A/B-03P October 2004
4
Preliminary
Parameter
Symbol
Test Condition
Min
--
V
DD
–0.5
--
5
RT9501A/B
Typ
0.4
--
--
--
Max
0.6
--
1.5
40
V
mA
Units
V
Output (Low) Voltage @ STAT pin V
STAT(LOW)
I
OL
= 10mA
Output (High) Voltage @ STAT pin V
STAT(HIGH)
I
OH
= 5mA
Output Low Voltage @ CC pin
Sink current @ CC pin
V
CC(LOW)
I
CC(SINK)
I
O(CC)
= 5mA ( sink )
Not to exceed power rating
specification (PD)
Note 1.
Stresses listed as the above
“Absolute
Maximum Ratings” may cause permanent damage to the device. These are for
stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended
periods may remain possibility to affect device reliability.
Note 2.
Devices are ESD sensitive. Handling precaution recommended.
Note 3.
The device is not guaranteed to function outside its operating conditions.
DS9501A/B-03P October 2004
5
