IC SMART BATTERY CHARGER 36SSOP

LTC1759CG#TRPBF

Manufacturer Part NumberLTC1759CG#TRPBF
DescriptionIC SMART BATTERY CHARGER 36SSOP
ManufacturerLinear Technology
LTC1759CG#TRPBF datasheet
 


Specifications of LTC1759CG#TRPBF

FunctionCharge ManagementBattery TypeSmart Batteries
Voltage - Supply11 V ~ 24 VOperating Temperature0°C ~ 70°C
Mounting TypeSurface MountPackage / Case36-SSOP (0.200", 5.30mm Width)
Lead Free Status / RoHS StatusLead free / RoHS Compliant  
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FEATURES
Single Chip Smart Battery Charger Controller
100% Compliant (Rev 1.0) SMBus Support
Allows for Operation with or without Host
SMBus Accelerator Improves SMBus Timing
Hardware Interrupt and SMBAlert Response
Eliminate Interrupt Polling
High Efficiency Synchronous Buck Charger
0.5V Dropout Voltage; Maximum Duty Cycle > 99.5%
AC Adapter Current Limit Maximizes Charge Rate*
1% Voltage Accuracy; 5% Current Accuracy
Up to 8A Charging Current Capability
Dual 10-Bit DACs for Charger Voltage and Current
Programming
User-Selectable Overvoltage and Overcurrent Limits
High Noise Immunity Thermistor Sensor
Small 36-Lead Narrow (0.209") SSOP Package
U
APPLICATIO S
Portable Computers
Portable Instruments
Docking Stations
*US Patent Number 5,723,970
U
TYPICAL APPLICATIO
AC
+
10 F
0.1 F
ADAPTER
35V
INPUT
V
DD
Al
0.1 F
33k
33k
3.83k
1 F
0.33 F
1.5k
0.68 F
1k
V
DD
475k
10k
1k
Smart Battery Charger
DESCRIPTIO
®
The LTC
charging solution that dramatically simplifies construc-
tion of an SBS compliant system. The LTC1759 imple-
ments a Level 2 charger function whereby the charger can
be programmed by the battery or by the host. A thermistor
on the battery being charged is monitored for tempera-
ture, connectivity and battery type information. The SMBus
interface remains alive when the AC power adapter is
removed and responds to all SMBus activity directed to it,
including thermistor status (via the ChargerStatus com-
mand). The charger also provides an interrupt to the host
whenever a status change is detected (e.g., battery
removal, AC adapter connection).
Charging current and voltage are restricted to chemistry
specific limits for improved system safety and reliability.
Limits are programmable by two external resistors. Addi-
tionally, the maximum average current from the AC adapter
is programmable to avoid overloading the adapter when
simultaneously supplying load current and charging cur-
rent. When supplying system load current, charging cur-
rent is automatically reduced to prevent adapter overload.
, LTC and LT are registered trademarks of Linear Technology Corporation.
15.8k
1k
0.033
LTC1759
7
22
499
UV
DCIN
16
21
V
DCDIV
0.47 F
DD
4
8
SYNC
INFET
5
32
1 F
SDB
V
CC
12
9
CHGEN
CLP
25
10
V
CLN
LIMIT
24
2
0.1 F
I
2.2 F
TGATE
LIMIT
33
18
DGND
BOOSTC
17
34
0.68 F
I
GBIAS
SET
1
28
PROG
BOOST
27
3
V
SW
C
35
11
COMP1
BGATE
6
30
AGND
SPIN
20
29
RNR
SENSE
19
31
THERM
BAT1
14
23
SDA
BAT2
15
26
SCL
V
SET
13
36
INTB
PGND
Figure 1. 4A SMBus Smart Battery Charger
LTC1759
U
1759 Smart Battery Charger is a single chip
SYSTEM
POWER
22 F
15 H
0.025
+
22 F
200
200
68
0.047 F
0.015 F
SMART
BATTERY
SMBus
INTB
TO
SCL
SDA
HOST
1759 F01
1

LTC1759CG#TRPBF Summary of contents

  • Page 1

    ... AC adapter is programmable to avoid overloading the adapter when simultaneously supplying load current and charging cur- rent. When supplying system load current, charging cur- rent is automatically reduced to prevent adapter overload. , LTC and LT are registered trademarks of Linear Technology Corporation. 15.8k 1k 0.033 LTC1759 ...

  • Page 2

    LTC1759 ABSOLUTE MAXIMUM (Note 1) Voltage UV, BAT1, CLP,CLN, SPIN, CC SENSE with respect to AGND ....................– 0.3V to 27V Voltage at DCIN, BAT2 with Respect to DGND ....................................................– 0.3V to 27V Voltage at ...

  • Page 3

    ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range ( DCIN = 18V 12.6V BAT1, 2 PARAMETER BOOST Pin Current V Threshold to Turn T ...

  • Page 4

    LTC1759 ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range ( DCIN = 18V 12.6V BAT1, 2 PARAMETER Thermistor Decoder (Note 11) Combined Input Leakage ...

  • Page 5

    ELECTRICAL CHARACTERISTICS The denotes specifications which apply over the full operating temperature range ( DCIN = 18V 12.6V BAT1, 2 PARAMETER Charger Timing Rise/Fall Time TGATE ...

  • Page 6

    LTC1759 W U TYPICAL PERFOR A CE CHARACTERISTICS Charger Efficiency 100 16.8V 95 12. 20V IN 70 0.5 1.5 2.5 3.5 CHARGING CURRENT (A) 1759 G09 Current from Battery vs Battery Voltage (Does Not ...

  • Page 7

    PIN FUNCTIONS Input Power-Related Pins UV (Pin 7): Charger Section Undervoltage Lockout Pin. The rising threshold is 6.7V with a hysteresis of 0.5V. Switching stops in undervoltage lockout. Connect this input to the input voltage source with ...

  • Page 8

    LTC1759 PIN FUNCTIONS V (Pin 27): This is the control signal of the inner loop of C the current mode PWM. Switching starts at 0.9V. Higher V corresponds to higher charging current in normal C operation. A ...

  • Page 9

    W BLOCK DIAGRA BAT1 – – SDB 5 + 1.3V ONE SYNC 4 SHOT AGND 92mV + CLP + 9 CL1 CLN – 10 COMP1 11 INTB 13 ...

  • Page 10

    LTC1759 TEST CIRCUITS V C 75k 0.047 0.65V 10 Test Circuit 1 LTC1759 – CA2 REF PROG 300 SET + LT1006 – 20k Test Circuit 2 LTC1759 + VA – V ...

  • Page 11

    U OPERATIO Overview (Refer to Block Diagram and Figure 10) The LTC1759 is composed of a battery charger section, a charger controller, two 10-bit DACs to control charger parameters, a thermistor decoder, limit decoder and an SMBus controller block. If ...

  • Page 12

    LTC1759 U OPERATIO Table 1: Supported Charger Functions SMBus ADDRESS FUNCTION (7-BIT) ChargerSpecInfo() b0001_001 ChargerMode() b0001_001 ChargerStatus() b0001_001 ChargingCurrent() b0001_001 ChargingVoltage() b0001_001 AlarmWarning() b0001_001 LTCVersionFunction() b0001_001 OptionalMfgFunction3() b0001_001 OptionalMfgFunction2() b0001_001 OptionalMfgFunction1() b0001_001 1 Alert Response Address b0001_100 1 Read-byte format. ...

  • Page 13

    U OPERATIO FUNCTION FIELD RESET_TO_ZERO Reserved ChargerStatus() CHARGE_INHIBITED MASTER_MODE VOLTAGE_NOTREG CURRENT_NOTREG LEVEL_3:LEVEL_2 CURRENT_OR VOLTAGE_OR THERM_OR THERM_COLD THERM_HOT POWER-ON WORD BIT RESET VALUE MAPPING (BINARY) ALLOWED VALUES 3 0 • 0 – Charging Value Unchanged • 1 – Set Charging Values ...

  • Page 14

    LTC1759 U OPERATIO FUNCTION FIELD THERM_UR ALARM_INHIBITED POWER_FAIL BATTERY_PRESENT AC_PRESENT ChargingCurrent() CHARGING_CURRENT [15:0] ChargingVoltage() CHARGING_VOLTAGE [15:0] AlarmWarning() OVER_CHARGED_ ALARM TERMINATE_CHARGE_ ALARM RESERVED_ALARM1 OVER_TEMP_ALARM 14 POWER-ON WORD BIT RESET VALUE ALLOWED VALUES MAPPING (BINARY) 11 Value • 0 – Thermistor Indicates ...

  • Page 15

    U OPERATIO FUNCTION FIELD TERMINATE_ DISCHARGE_ALARM Reserved REMAINING_ CAPACITY_ALARM REMAINING_TIME_ ALARM INITIALIZED DISCHARGING FULLY_CHARGED FULLY_DISHARGED ERROR LTCVersionFunction LTC_VERSION () SMBus Accelerator Pull-Ups Both SCL and SDA have SMBus accelerator circuits which reduce the rise time on systems with significant capaci- ...

  • Page 16

    LTC1759 U OPERATIO The Charger Controller Block The LTC1759 charger operations are handled by the charger controller block. This block is capable of charging the selected battery autonomously or under host control. The charger controller can request communications with the ...

  • Page 17

    U OPERATIO Table 3. Charger_Controller Functional Features # CONDITION 0 POWER_ON_RESET = 1 1 CHARGING_RESET_STATE = 1 AND the Battery Is Present AND AC_PRESENT = 1 AND INHIBIT_CHARGE = 0 AND Thermistor Is Ideal 2 CHARGING_RESET_STATE = 1 AND the ...

  • Page 18

    LTC1759 U OPERATIO # CONDITION 12 CHARGING_CONTROLLED_STATE = 1 AND THERM_HOT Changes from AND THERM_UR = 0 13 CHARGING_CONTROLLED_STATE = 1 AND THERM_UR Changes from AND THERM_HOT = 1 14 CHARGING_CONTROLLED_STATE = 1 AND ...

  • Page 19

    U OPERATIO The Thermistor Decoder Block This block measures the resistance of the battery’s ther- mistor and features high noise immunity at critical trip points. The low power standby mode supports all SMB charger reporting requirements when AC is not ...

  • Page 20

    LTC1759 U OPERATIO When AC power is not available the thermistor block supports the following low power operating features: 1. Only the low power THERM_OR detection circuitry is kept alive to support battery present interrupts. 2. The ChargeStatus() read function ...

  • Page 21

    U OPERATIO Table 7. V Trip Points and Ranges LIMIT NOMINAL EXTERNAL CHARGING RESISTOR VOLTAGE ( VOLTAGE RANGE VLIMIT LIMIT 0 V < 0.09V 2465mV < V VLIMIT VCCP < 8432mV 10k 1% 0.17V < V 2465mV ...

  • Page 22

    LTC1759 U OPERATIO When wake-up is asserted to the current DAC block, the delta-sigma is then fixed at a value equal to 80mA, inde- pendent of the I setting. LIMIT Note: The external resistor connected to the I multiplied by ...

  • Page 23

    U U APPLICATIONS INFORMATION Charge Termination Issues Batteries with constant current charging and voltage- based charger termination might experience problems with reductions of charger current caused by adapter limiting recommended that input limiting feature be defeated in such ...

  • Page 24

    LTC1759 U U APPLICATIONS INFORMATION Step 1: Determine R . Using your chosen I SENSE your maximum charge current, calculate the sense resis- tor value and round to the nearest standard value. Any rounding error is made up by the ...

  • Page 25

    U U APPLICATIONS INFORMATION voltage will be pulled down by the constant 30W load until it reaches a lower stable state where the switching regu- lators can no longer supply full load. This situation can be prevented by utilizing the ...

  • Page 26

    LTC1759 U U APPLICATIONS INFORMATION below ground with the full battery potential, causing a potential for latch-up in any of the devices connected to the SMBus inputs. Therefore it is good design practice to protect the SMBus inputs as shown ...

  • Page 27

    ... R6 3.3V = 330k 5V = 680k Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights crude voltage level detector looking for voltage going below approximately one volt on the emitter ...

  • Page 28

    ... High Efficiency Constant-Current/Constant-Voltage Charger LT1511 Monolithic 3A Constant-Current/Constant-Voltage Charger LTC1694 SMBus Accelerator in SOT-23 Package LT1769 Monolithic 2A Constant-Current/Constant-Voltage Charger PowerPath is a trademark of Linear Technology Corporation. Linear Technology Corporation 28 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear-tech.com 4A SMBus Smart Battery Charger ...