LTC4100 Linear Technology, LTC4100 Datasheet
LTC4100
Available stocks
Related parts for LTC4100
LTC4100 Summary of contents
Page 1
... SMBDAT DESCRIPTIO The LTC charging solution that dramatically simplifies construc- tion of an SBS compliant system. The LTC4100 imple- ments a Level 2 charger function whereby the charger can be programmed by the battery or by the host. A SafetySignal on the battery being charged is monitored for tempera- ture, connectivity and battery type information. The SMBus ...
Page 2
... V CLP CLN CSP BAT DCIN Rising BAT Part Held in Reset Until this V Present CHGEN V 28V DCIN ORDER PART NUMBER 24 CLP 23 CLN LTC4100EG BAT 22 21 CSP SET THA 16 15 THB 14 V LIM 13 I LIM = 90 C/W = 12V unless otherwise noted ...
Page 3
... BGATE C = 3000pF, 10% to 90% LOAD C = 3000pF, 10% to 90% LOAD C = 3000pF, 10% to 90% LOAD C = 3000pF, 10% to 90% LOAD - –1 A TGATE TGATE TGATE LTC4100 = 12V unless otherwise noted. (Note 4) BAT MIN TYP MAX 140 165 200 – 1.4V –40 = 1.4V 40 1.5 93 100 107 100 1 = 1.4V 36 ...
Page 4
... LTC4100 ELECTRICAL CHARACTERISTICS temperature range, otherwise specifications are at T SYMBOL PARAMETER AC Present Comparator V DCDIV Threshold ACP DCDIV Hysteresis DCDIV Input Bias Current ACP V OH ACP V OL DCDIV to ACP Delay SafetySignal Decoder SafetySignal Trip (RES_COLD/RES_OR) SafetySignal Trip (RES_IDEAL/RES_COLD) SafetySignal Trip (RES_HOT/RES_IDEAL) SafetySignal Trip (RES_UR/RES_HOT) ...
Page 5
... Note 2: See Test Circuit. Note 3: Does not include tolerance of current sense resistor. Note 4: The LTC4100E is guaranteed to meet performance specifications from Specifications over the – operating temperature range are assured by design, characterization and correlation with statistical process controls ...
Page 6
... SafetySignal is 1nF (see Figure 4). A series resistor 1130 needs to be connected between this pin and the battery’s SafetySignal for this circuit to work correctly. V (Pin 17): Power Supply Input for the LTC4100 Digital DD Circuitry. Bypass this pin with 0.1 F. Typically between 3.3V and 5V ...
Page 7
... SMBus INTERFACE AND CONTROL DECODER THERMISTER INTERFACE Figure 2. LTC4100 + 1.19V – EA – TOL V DAC BAT V I SET TH LT1055 + – 0.6V 4100 TC01 LTC4100 V BAT BAT 22 R SENSE CSP – – 17mV + – + 1.19V 10-BIT I DAC ACP ...
Page 8
... LTC4100 U OPERATIO Overview (Refer to Block Diagram) The LTC4100 is composed of a battery charger section, a charger controller, a 10-bit DAC to control charger cur- rent, an 11-bit DAC to control charger voltage, a SafetySignal decoder, limit decoder and an SMBus controller block battery is present, the SafetySignal decoder indicates a RES_OR condition and charging is disabled by the charger controller (CHGEN = Low) ...
Page 9
... ChargerMode() ('h12) Description: The SMBus Host uses this command to set the various charger modes. The default values are set to allow a Smart Battery and the LTC4100 to work in concert without requiring an SMBus Host. Purpose: Allows the SMBus Host to configure the charger and change the default modes. This is a write only func- tion, but the value of the “ ...
Page 10
... CHARGING_CURRENT[15:0] Permitted Unsigned integer representing current in mA Values 8'h15 Value CHARGING_VOLTAGE[15:0] Permitted Unsigned integer representing voltage in mV Values 8'h16 Control Permitted Values 1/0 1/0 1/0 1/0 8'h3C Register Reserved LTC4100's Version Identification Permitted Ignored 1/0 Values Return Values 1 N/A Status Not Supported Return Values ...
Page 11
... Battery Charger. CURRENT_OR bit is set only when ChargingCurrent() is set to a value outside the current regulation range of the LTC4100. This bit may be used in conjunction with the INHIBIT_CHARGE bit of the ChargerMode() and ChargingCurrent() to determine the current capability of the LTC4100. When ChargingCurrent() is set to the pro- grammatic maximum current + 1, the CURRENT_OR bit will be set ...
Page 12
... AlarmWarning() message to the LTC4100 to notify it that one or more alarm conditions exist. Alarm indications are encoded as bit fields in the Battery’s Status register, which is then sent to the LTC4100 by this func- tion. Purpose: The LTC4100 will use the information sent by Current this function to properly charge the battery ...
Page 13
... U OPERATIO Purpose: This function allows the SMBus Host to deter- mine if the battery charger is an LTC4100. Identifying the manufacturer and version of the Smart Battery Charger permits software to perform tasks specific to a given charger. The LTC4100 also provides a means of disabling the LOWI current mode of the I DAC • ...
Page 14
... Battery’s ability to transmit ChargingCurrent() and ChargingVoltage() request functions and broadcasting the charging commands to the LTC4100 over the SMBus. 4. The LTC4100 will still respond to Smart Battery critical warning messages without host intervention. Wake-up Charging Mode The following conditions must be met in order to allow wake-up charging of the battery: 1 ...
Page 15
... THB_SELB, a selectable reference generator, and two comparators. This circuit has two modes of operation based upon whether AC is present. When AC is present, the LTC4100 samples the value of the SafetySignal and updates the ChargerStatus register ap- proximately every 32ms. The state machine successively ...
Page 16
... C represents the capacitance between the SafetySignal SS and GND. C may be added to provide additional noise SS immunity from transients in the application. C exceed 1nF if the LTC4100 is to properly sense the value SafetySignal The I Decoder Block LIM The value of an external resistor connected from this pin to GND determines one of four current limits that are used for maximum charging current value ...
Page 17
... PROGRAMMED VALUE (V) NOTE: THE LTC4100 CAN BE PROGRAMMED WITH ChargingVoltage() FUNCTION VALUES BETWEEN 1.184V AND 2.9V, HOWEVER, THE BATTERY CHARGER CONTROLLER OUTPUT VOLTAGE MAY BE ZERO WITH PROGRAMMED VALUES BELOW 2.9V. Figure 6. Transfer Function of Charger The Current DAC Block The current DAC is a delta-sigma modulator which con- trols the effective value of an external resistor set the current limit of the charger ...
Page 18
... U U APPLICATIO S I FOR ATIO Adapter Limiting An important feature of the LTC4100 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. ...
Page 19
... decreases Example 320mW Soft Start and Undervoltage Lockout The LTC4100 is soft started by the 0.12 F capacitor on the I pin. On start-up then ramp rate set by the internal 30 A pull-up ). Remember the MAX current and the external capacitor. Battery charging current starts ramping up when I ...
Page 20
... LTC4100 U U APPLICATIO S I FOR ATIO In any switching regulator, conventional timer-based soft starting can be defeated if the input voltage rises much slower than the time out period. This happens because the switching regulators in the battery charger and the com- puter power supply are typically supplying a fixed amount of power to the load ...
Page 21
... IC is essential. (See Figure 11.) Here is a PCB layout priority list for proper layout. Layout the PCB using this specific order 4100 F13 LTC4100 SWITCH NODE L1 HIGH FREQUENCY ...
Page 22
... Interfacing with a Selector The LTC4100 is designed to be used with a true analog multiplexer for the SafetySignal sensing path. Some se- lector ICs from various manufacturers may not implement this ...
Page 23
... LTC DWG # 05-08-1640) 1.25 0. 5.3 – 5.7 0.65 BSC – 8 0.65 (.0256) BSC 0.22 – 0.38 (.009 – .015) LTC4100 7.90 – 8.50* (.311 – .335 7.40 – 8.20 (.291 – .323) 2.0 (.079) 0.05 (.002) G24 SSOP 0802 sn4100 4100is 23 ...
Page 24
... LTC4100 U TYPICAL APPLICATIO LTC4100 Li-Ion Battery Charger I 15V TO 20V DCIN FROM WALL C1 ADAPTER 0.1 F R11 1.21k 1% C6, 0.12 F 10V, X7R C7, 0.0015 F 10V, X7R C8, 0.082 F 10V, X7R 0.1 F 10V R6 5.5V 10k 10k D2 SDA D3 D4 SCL D5 RELATED PARTS PART NUMBER DESCRIPTION LTC1760 Smart Battery System Manager ...