LTC4015_15 Datasheet, PDF (55/76 Pages) Linear Technology – Multichemistry Buck Battery Charger Controller with Digital Telemetry System

LTC4015
Register Descriptions
SYMBOL
ok_to_charge
no_rt
thermal_shutdown
vin_ovlo
vin_gt_vbat
intvcc_gt_4p3v
intvcc_gt_2p8v
VBAT
VIN
VSYS
IBAT
IIN
DIE_TEMP
NTC_RATIO
BSR
JEITA_REGION
CHEM_CELLS
chem
reserved
cell_count_pins
ICHARGE_DAC
VCHARGE_DAC
IIN_LIMIT_DAC
SUB R/W ACTIVE DESCRIPTION
ADDR
BITS
6
indicates all system conditions are met to allow battery charger
operation
5 indicates no resistor has been detected at the rt pin
4 indicates die temperature is greater than thermal shutdown level
(160°C typical)
3 indicates vin voltage is greater than overvoltage lockout level
(38.6V typical)
2 indicates vin voltage is sufficiently greater than batsens for switching
charger operation (200mV typical)
1 indicates INTV_CC voltage is above switching charger undervoltage
lockout level (4.3V typ)
0 indicates INTV_CC voltage is greater than measurement system lockout
level (2.8V typical)
0x3A R
0x3B R
0x3C R
0x3D R
0x3E R
0x3F R
15:0 Two’s complement ADC measurement result for the BATSENS pin.
V_BATSENS/cellcount = [VBAT] • 192.264µV for lithium chemistries.
V_BATSENS/cellcount = [VBAT] • 128.176µV for lead-acid.
15:0 Two’s complement ADC measurement result for V_IN.
V_VIN = [VIN] • 1.648mV
15:0 Two’s complement ADC measurement result for V_SYS.
V_SYS = [VSYS] • 1.648mV
15:0 Two’s complement ADC measurement result for (V_CSP – V_CSN). Charge
current (into the battery) is represented as a positive number. Battery
current = [IBAT] • 1.46487µV/R_SNSB
15:0 Two’s complement ADC measurement result for (V_CLP – V_CLN). Input
current = [IIN] • 1.46487µV/R_SNSI
15:0 Two’s complement ADC measurement result for die temperature.
Temperature = (DIE_TEMP – 12010)/45.6°C
0x40 R
0x41 R
0x42 R
15:0 Two’s complement ADC measurement result for NTC thermistor ratio.
R_NTC = NTC_RATIO • R_NTCBIAS/(21845.0 – NTC_RATIO)
15:0 Calculated battery series resistance.
For lithium chemistries, series resistance/cellcount = BSR • R_SNSB/500.0
For lead-acid chemistries, series resistance/cellcount = BSR • R_SNSB/750.0
2:0 JEITA temperature region of the NTC thermistor (Li Only). Active only
when EN_JEITA=1
0x43 R 11:0 Readout of CHEM and CELLS pin settings
11:8 programmed battery chemistry
7:4 Reserved
3:0 cell count as set by CELLS pins
0x44 R 4:0 Charge current control DAC control bits
0x45 R 5:0 Charge voltage control DAC control bits
0x46 R 5:0 Input current limit control DAC control word
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For more information www.linear.com/LTC4015
4015f
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