Document
Preliminary
RT9541
Li-Ion Battery Protector
General Description
The RT9541 Series are protection ICs for overcharge/discharge of rechargeable one-cell Lithium-ion (Li+) batteries by CMOS process.
The RT9541 Series can detect over-charge/discharge of Li+ one-cell and excess load current and charge current, further include a short circuit protector for preventing large external short circuit current.
Each of these ICs is composed of four voltage detectors, a reference unit, a hysteresis circuit, and a bidirectional short circuit protector. Package of SOT26 is available.
Ordering Information
RT9541
Package type E : SOT-26 Type I ER : SOT-26 Type II
Operating temperature range C: Commercial standard See Table 1
Typical Application Circuit
R1 100Ω
+
C1 0.1µF
CT
C3 0.01µF
VSS
VDD RT9541
V-
DOUT COUT
C2 0.1µF
R2 1KΩ
Features
z Low supply current − Supply current: TYP. 2.0µA − Standby current (after detecting overdischarge): Less than 0.2µA
z High accuracy detector threshold − Over-charge detector: ±25mV − Over-discharge detector: ±2.5%
z Built-in protection circuit − Excess current trip/Short circuit protector in both charging and discharging direction
z Output delay of over-charge adjustable with an external capacitor: 75mS at 0.01µF
z Ultra small package: SOT26
Applications
z Over-charge / Over-discharge Protection for Li+ One-cell Pack
z High Precision Protectors for Cellular Phones or Instruments Using Li+ One-cell Battery
Pin Configurations
Part Number
RT9541
CE (Plastic SOT-26)
Pin Configurations TOP VIEW
65 4 123
1. COUT 2. CT 3. VSS 4. DOUT 5. VDD 6. V-
RT9541
CER (Plastic SOT-26)
65 4 123
TOP VIEW
1. DOUT 2. V3. COUT 4. CT 5. VDD 6. VSS
DS9541-05 August 2001
www.richtek-ic.com.tw
1
RT9541
Absolute Maximum Ratings
z Allowable Battery Voltage z Input Voltage (V) z Input Voltage (CT) z Output Voltage (COUT) z Output Voltage (DOUT) z Power Dissipation, PD @ TA = 25°C
SOT-26 z Package Thermal Resistance
SOT-26, θJA z Operating Temperature Range z Storage Temperature Range
Preliminary
-0.3V ~ 7V VDD-14V to VDD +0.3V VSS-0.3V to VDD +0.3V VDD-14V to VDD +0.3V VSS-0.3V to VDD +0.3V
0.25W
250°C/W -20°C ~ +85°C -65°C ~ +150°C
Electrical Characteristics
Parameter
Symbol
Test Conditions
Min Typ Max Units
Operating Input Voltage
VDD
Charger Voltage
VCHG
Minimum Operating Voltage for 0V Charging
Voltage defined as VDD-VSS
Voltage defined as VDD-V-
Voltage defined as VDD-VVDD-VSS = 0V
1 --
--
-- 6 V -- 14 V
-- 1 V
Accuracy of Over-charge Threshold Voltage
∆VOCHG
Detect rising edge of supply voltage
-25
--
25 mV
Over-charge Threshold Hysteresis
0.1 0.15 0.2 V
Output Delay Time of Over-charge TOCHG
C3 = 0.01µF, VDD = 3.6V ~ 4.3V
30
60
80 mS
Accuracy of Over-discharge Threshold Voltage
∆VODISCHG
Detect falling edge of supply voltage
-2.5
--
2.5 %
Output Delay Time of Overdischarge
TODISCHG VDD = 3.6V ~ 2.4V
10 15 20 mS
Excess Current Threshold Voltage During Discharge
Detect rising edge of “V-“ pin voltage
0.15
0.17
0.19
V
Output Delay of Discharge Excess Current
VDD = 3.0V
15 20 25 mS
Excess Current Threshold Voltage During Charge
Detect falling edge of “V-“ pin voltage
-0.19
-0.17
-0.15
V
Output Delay of Charge Excess Current
15 20 25 mS
Short Detection Voltage During Discharge
VDD = 3.0V
VDD-1.1 VDD-0.8 VDD-0.5 V
Output Delay of Discharge Short Circuit
TSHORT
VDD = 3.0V
-- 5 50 µS
Reset Resistance for Excess Current Protection
RSHORT VDD = 3.6V, V- = 1.0V
25 50 75 kΩ
Supply Current Standby Current
IDD ISTANDBY
VDD = 3.9V, V- = 0V VDD = 2.0V
-- 2.0 5.0 µA -- 0.1 0.5 µA
www.richtek-ic.com.tw
2
DS9541-05 August 2001
Preliminary
RT9541
Table 1
Part Number
RT9541ACE (R) RT9541BCE (R) RT9541CCE (R) RT9541DCE (R) RT9541ECE (R) RT9541FCE (R) RT9541GCE (R) RT9541HCE (R) RT9541ICE (R) RT9541JCE (R)
Over
Over Excess
Charge Discharge Current
4.25V
2.3V
170mV
4.25V
2.4V
170mV
4.25V
2.5V
170mV
4.25V
2.6V
170mV
4.25V
2.7V
170mV
4.25V
2.8V
170mV
4.30V
2.3V
170mV
4.30V
2.4V
170mV
4.30V
2.5V
170mV
4.30V
2.6V
170mV
Function Block Diagram
VDD
CT
Part Number
RT9541KCE (R) RT9541LCE (R) RT9541MCE (R) RT9541NCE (R) RT9541OCE (R) RT9541PCE (R) RT9541QCE (R) RT9541RCE (R) RT9541SCE (R) RT9541TCE (R)
Over
Over Excess
Charge Discharge Current
4.30V
2.7V
170mV
4.30V
2.8V
170mV
4.35V
2.3V
170mV
4.35V
2.4V
170mV
4.35V
2.5V
170mV
4.35V
2.6V
170mV
4.35V
2.7V
170mV
4.35V
2.8V
170mV
4.35V
2.9V
170mV
4.25V
2.9V
170mV
_ _
+ +
VD1 _ VD4
VD2 _
VD3
++
Level Shift
Delay
Short Circuit Detector
Pin Description
VSS
Pin Number Pin Name
RT9541-
CE RT9541-
CER
1 3 COUT
2 4 CT
3 6 VSS
4 1 DOUT
5 5 VDD
6 2 V-
DOUT COUT V-
Pin Function
Output of Over-charge Detection, CMOS Output Pin for External Capacitor Setting Output Delay of VD1 Ground Output of Over-discharge Detection, CMOS Output Power Supply, through a Resistor (R1) Pin for Charger Negative Input, through a Resistor (R2).