Datasheet LT1505 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Constant-Current/Voltage High Efficiency Battery Charger |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTIO. Simple Charging of Li-Ion, NiMH and NiCd Batteries. … |
| File Format / Size | PDF / 170 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Simple Charging of Li-Ion, NiMH and NiCd Batteries. Very High Efficiency: Up to 97%
Model Line for this Datasheet
Text Version of Document
LT1505 Constant-Current/Voltage High Efficiency Battery Charger
U FEATURES DESCRIPTIO
■
Simple Charging of Li-Ion, NiMH and NiCd Batteries
The LT®1505 PWM battery charger controller fast charges ■
Very High Efficiency: Up to 97%
multiple battery chemistries including lithium-ion (Li-Ion), ■
Precision 0.5% Charging Voltage Accuracy
nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) ■
Preset Battery Voltages: 12.3V, 12.6V,
using constant-current or constant-voltage control. Maxi-
16.4V and 16.8V
mum current can be easily programmed by resistors or a ■
5% Charging Current Accuracy
DAC. The constant-voltage output can be selected for 3 or 4 ■
Charging Current Programmed by Resistor or DAC
series Li-Ion cells with 0.5% accuracy. ■
0.5V Dropout Voltage, Duty Cycle > 99.5%
A third control loop limits the current drawn from the AC ■ AC Adapter Current Limit* Maximizes Charging Rate adapter during charging*. This allows simultaneous opera- ■ Flag Indicates Li-Ion Charge Completion tion of the equipment and fast battery charging without over- ■ Auto Shutdown with Adapter Removal loading the AC adapter. ■ Only 10µA Battery Drain When Idle ■ Synchronizable Up to 280kHz The LT1505 can charge batteries ranging from 2.5V to 20V with dropout voltage as low as 0.5V. Synchronous
U
N-channel FETs switching at 200kHz give high efficiency
APPLICATIO S
and allow small inductor size. A diode is not required in ■ series with the battery because the charger automatically Notebook Computers ■ enters a 10µA sleep mode when the wall adapter is un- Portable Instruments ■ plugged. A logic output indicates Li-Ion full charge when Chargers for Li-Ion, NiMH, NiCd and Lead Acid current drops to 20% of the programmed value. Rechargeable Batteries The LT1505 is available in a 28-pin SSOP package. , LTC and LT are registered trademarks of Linear Technology Corporation. *US Patent No. 5,723,970
U TYPICAL APPLICATION
M3 TO Si4435 SYSTEM POWER DBODY* C4 D3 RS4 0.1µF MMSD4148T1 VIN 0.025Ω (FROM C ADAPTER) IN VCC BOOST BOOSTC C3 C2 D2 C1 R7 47µF 2.2µF 0.68 MMSD4148T1 µF 1µF GBIAS 500Ω 35V M1 L1 RS1 CLN TGATE 100k Si4412 15µH 5Ω 0.025Ω CLP SW VBAT R5 M2 D4 COUT 4k INFET BGATE Si4412 MBRS140 22µF 12.6V 25V BATTERY UV VC ×2 R6 SYNC PROG 4k LT1505 SHDN 3 CELL 300Ω RX4 3k FLAG VFB C R R PROG S2 S3 0.33µF CAP 4.2V 1µF 200Ω 200Ω *BODY DIODE 1% 1% POLARITY MUST RPROG COMP1 4.1V BE AS SHOWN 4.93k R1 AGND 1% 1k * DBODY IS THE BODY DIODE OF M3 C6 C7 PGND C 0.1µF 0.68µF IN: SANYO OS-CON L1: SUMIDA CDRH127-150 BAT2 BAT SENSE SPIN (CAN BE FROM 10µH TO 30µH) 1505 F01
Figure 1. Low Dropout 4A Lithium-Ion Battery Charger
1505fc 1
U FEATURES DESCRIPTIO
■
Simple Charging of Li-Ion, NiMH and NiCd Batteries
The LT®1505 PWM battery charger controller fast charges ■
Very High Efficiency: Up to 97%
multiple battery chemistries including lithium-ion (Li-Ion), ■
Precision 0.5% Charging Voltage Accuracy
nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd) ■
Preset Battery Voltages: 12.3V, 12.6V,
using constant-current or constant-voltage control. Maxi-
16.4V and 16.8V
mum current can be easily programmed by resistors or a ■
5% Charging Current Accuracy
DAC. The constant-voltage output can be selected for 3 or 4 ■
Charging Current Programmed by Resistor or DAC
series Li-Ion cells with 0.5% accuracy. ■
0.5V Dropout Voltage, Duty Cycle > 99.5%
A third control loop limits the current drawn from the AC ■ AC Adapter Current Limit* Maximizes Charging Rate adapter during charging*. This allows simultaneous opera- ■ Flag Indicates Li-Ion Charge Completion tion of the equipment and fast battery charging without over- ■ Auto Shutdown with Adapter Removal loading the AC adapter. ■ Only 10µA Battery Drain When Idle ■ Synchronizable Up to 280kHz The LT1505 can charge batteries ranging from 2.5V to 20V with dropout voltage as low as 0.5V. Synchronous
U
N-channel FETs switching at 200kHz give high efficiency
APPLICATIO S
and allow small inductor size. A diode is not required in ■ series with the battery because the charger automatically Notebook Computers ■ enters a 10µA sleep mode when the wall adapter is un- Portable Instruments ■ plugged. A logic output indicates Li-Ion full charge when Chargers for Li-Ion, NiMH, NiCd and Lead Acid current drops to 20% of the programmed value. Rechargeable Batteries The LT1505 is available in a 28-pin SSOP package. , LTC and LT are registered trademarks of Linear Technology Corporation. *US Patent No. 5,723,970
U TYPICAL APPLICATION
M3 TO Si4435 SYSTEM POWER DBODY* C4 D3 RS4 0.1µF MMSD4148T1 VIN 0.025Ω (FROM C ADAPTER) IN VCC BOOST BOOSTC C3 C2 D2 C1 R7 47µF 2.2µF 0.68 MMSD4148T1 µF 1µF GBIAS 500Ω 35V M1 L1 RS1 CLN TGATE 100k Si4412 15µH 5Ω 0.025Ω CLP SW VBAT R5 M2 D4 COUT 4k INFET BGATE Si4412 MBRS140 22µF 12.6V 25V BATTERY UV VC ×2 R6 SYNC PROG 4k LT1505 SHDN 3 CELL 300Ω RX4 3k FLAG VFB C R R PROG S2 S3 0.33µF CAP 4.2V 1µF 200Ω 200Ω *BODY DIODE 1% 1% POLARITY MUST RPROG COMP1 4.1V BE AS SHOWN 4.93k R1 AGND 1% 1k * DBODY IS THE BODY DIODE OF M3 C6 C7 PGND C 0.1µF 0.68µF IN: SANYO OS-CON L1: SUMIDA CDRH127-150 BAT2 BAT SENSE SPIN (CAN BE FROM 10µH TO 30µH) 1505 F01
Figure 1. Low Dropout 4A Lithium-Ion Battery Charger
1505fc 1
