LTC1759 Linear Technology, LTC1759 Datasheet

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... 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 ...

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... All Connected Pins UV Charging 5.5V, Shorted Thermistor DD Not Charging 5.5V DD 2.465V V V BAT2 MAX R Tolerance = 1% SET U W INFORMATION TOP VIEW ORDER PART NUMBER 36 PGND 35 BGATE 34 GBIAS LTC1759CG 33 BOOSTC BAT1 30 SPIN 29 SENSE 28 PROG SET 25 V LIMIT 24 I LIMIT 23 BAT2 ...

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... V = Low SDB TGATE BGATE V Rising from 0.8V to 1.2V DCDIV DCDIV AC_PRESENT = DCIN ) AC_PRESENT = DCIN SYNC SYNC LTC1759 = 100 C), otherwise specifications are J MIN TYP MAX 6.8 7.1 7.3 0. 100 108 – 50 –120 –10 – 0.25 V – 0.3 ...

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... 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 on RNR and THERM Thermistor Trip (COLD/OR) Thermistor Trip (IDEAL/COLD) Thermistor Trip (HOT/IDEAL) Thermistor Trip (UR/HOT) ...

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... See Smart Battery Charger Specification (Revision 1.0), section 6.1.3 and 6.1.8. Note 9: In system start-up, C6 (boost capacitor) has no charge stored in it. The LTC1759 will keep TGATE off, and turn BGATE on for 0.2 s, thus charging C6. A comparator senses V PWM mode when V Note 10: Refer to Smart Battery Charge Specification (Revision 1.0), section 6 ...

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... PROG R = 3.83k SET 200 150 100 100 150 200 250 CHARGING CURRENT (mA) 1759 G01 6 SMBus Accelerator Operation 200pF LTC1759 R = 15k PULLUP 0V 1 s/DIV (Not Charging 120 110 100 3.0 3.5 4.0 4.5 5.0 V (V) ...

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... GBIAS BOOST CC Electrical Characteristics table for more information. V (Pin 26): This is the tap point of the programmable SET resistor divider, which provides battery voltage feedback to the charger. LTC1759 with connected from I to the SET SET divider. See SET 7 ...

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... Host. Signals host that there has been a change of status in the charger registers and that the host should read the , this pin can be left LTC1759 status registers to determine if any action on its part is required. This signal can be connected to the optional SMBALERT# line of the SMBus. Open drain with weak current source pull- pulled to 5V externally, see Figure 2) ...

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... V REF CA2 – 75k + AC_PRESENT V – – PWR_FAIL + CHARGER CONTROLLER VOLTAGE THERMISTOR DECODER DECODER SMBus 13 CONTROLLER CURRENT Figure 2 LTC1759 INFET 1 BOOST 2 TGATE 3 SW 8.9V 34 GBIAS 35 BGATE 36 PGND 33 BOOSTC 30 SPIN + 29 SENSE CA1 – BAT1 28 PROG – V REF DCDIV ...

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... 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 REF PROG I PROG 2k – LT1013 + + 0. SET 2.465V SPIN R S3 200 SENSE + R R SENSE CA1 ...

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... 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 battery is present, the thermistor decoder indicates a THERM_OR condition and charging is disabled by the charger controller (CHGEN = Low) ...

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... OptionalMfgFunction3() b0001_001 OptionalMfgFunction2() b0001_001 OptionalMfgFunction1() b0001_001 1 Alert Response Address b0001_100 1 Read-byte format. 89h is returned as the interrupt address of the LTC1759. Rev 1.0 SMBus Compliant. Table 2: SMBus Word Bit Definitions for All Allowed LTC1759 Functions FUNCTION FIELD ChargerSpecInfo CHARGER_SPEC SELECTOR_SUPPORT Reserved ChargerMode() INHIBIT_CHARGE ENABLE_POLLING ...

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... Read Only. Write Will NACK 9 Value • 0 – Thermistor Indicates Not Cold • 1 – Thermistor Indicates Cold • Read Only. Write Will NACK 10 Value • 0 – Thermistor Indicates Not Hot • 1 – Thermistor Indicates Hot • Read Only. Write Will NACK LTC1759 13 ...

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... 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 Not Underrange • 1 – Thermistor Indicates Underrange • ...

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... Intended for Host • Not Supported by LTC1759 • Write Only. Read Will NACK 5 – • Intended for Host • Not Supported by LTC1759 • Write Only. Read Will NACK 4 – • Intended for Host • Not Supported by LTC1759 • Write Only. Read Will NACK 3:0 – ...

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... Battery’s ability to transmit ChargingCurrent() and ChargingVoltage() request functions and broadcasting the charging commands to the LTC1759 over the SMBus. 4. The LTC1759 will still respond to Smart Battery critical warning messages without host intervention. The charger controller block uses the state machine of Figure 3. The functional features for state transitions and general control are detailed in Table 3 ...

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... Up” Charge Again Until Condition 15 Is Met. It Can Supply “Controlled Charge” to the Battery If Conditions Are Met CHARGING_NONE_STATE = 1 The Charger_Controller Stops Charging the Battery. It Cannot “Wake Up” Charge Again Until Condition 15 Is Met. It Can Supply “Controlled Charge” to the Battery If Conditions Are Met LTC1759 17 ...

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... 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 INHIBIT_CHARGE Is Set ANY STATE The Charger_Controller Is in Any State AND (the Battery Is Removed OR AC_PRESENT = Written to POR_RESET) NOTE: Condition 15 Takes Precedence Over Any Other Condition ...

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... HOT tested high. resistor forms WEAK NOTE: The underrange detection scheme is a very impor- tant feature of the LTC1759. The R point of 0.333 • V (140mV) threshold of a system using a 10k pull-up. A system using a 10k pull-up would not be able to resolve the important underrange to hot transition point with a mod- est 100mV of ground offset between battery and ther- mistor detection circuitry ...

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... 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 forces the thermistor block to update thermistor status at the beginning of the read ...

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... The delta-sigma output gates this low duty cycle MAX . signal on and off. The delta-sigma shift registers are then clocked at a slower rate, about 45ms/bit, so that the charger has time to settle to the I average charging current is equal to that requested by the ChargingCurrent() value. LTC1759 ...

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... U APPLICATIONS INFORMATION Adapter Limiting An important feature of the LTC1759 is the ability to automatically adjust charging current to a level which avoids overloading the wall adapter. This allows the prod- uct to operate at the same time that batteries are being charged without complex load management algorithms. ...

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... Consult the battery manufacturer for information on how your battery terminates charging. Setting Output Current Limit (Refer to Figure 10) The LTC1759 current DAC and the PWM analog circuitry must coordinate the setting of the charger current. Failure will result in incorrect charge currents. ...

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... (18V – 8.9V)(230kHz • 40nC) + 18V • 20mA D = 437mW SENSE Soft Start and Undervoltage Lockout The LTC1759 is soft started by the 0.33 F capacitor on the . This is simply a V pin. On start-up, V value. See the Electri- C then ramp rate set by the internal 45 A pull-up values ...

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... If the battery contains a static charge, the SMBus inputs are subjected to ESD which can cause damage after repeated exposure. Also, if the battery’s positive terminal makes contact to the connector before the negative terminal, the SMBus inputs can be forced LTC1759 V BAT 0. – ...

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... For best current programming accuracy provide a Kelvin connection from example. Interfacing with a Selector The LTC1759 is designed to be used with a true analog multiplexer for the thermistor sensing path. Some selec- tor ICs from various manufacturers may not implement this. Consult LTC applications department for more infor- mation ...

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... INFORMATION Charging Indication When a CHARGECURRENT() command with a value of zero is sent to the LTC1759, current stops flowing into the battery. However, the command does not cause the CHGEN pin to pull low. This prevents use of the CHGEN pin as a charge termination indication. Figure 16 shows a circuit that reliably indicates when the battery is receiving a charge current ...

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... 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 R1 R2 15. 0.033 CL Q1 LTC1759 DCIN 499 DCDIV DD 0. SYNC ...