LTC3577_15 Datasheet, PDF (43/54 Pages) Linear Technology – Highly Integrated 6-Channel Portable PMIC

LTC3577/LTC3577-1
OPERATION
battery has returned to a valid charging temperature. A 0
in bit A0 indicates that charging has entered the end-of-
charge state (h_C/10) and is near V_FLOAT or that charging
has been terminated. Charging can be terminated by
reaching the end of the charge timer or by a battery fault
as described previously.
I²C WRITE REGISTER MAP (see the “I²C Input Data” section
for more details, all registers default to 0 when reset)
LDO and BUCK CONTOL
REGISTER
BIT NAME
B0 LDO1EN
B1 LDO2EN
B2 BK1BRST
B3 BK2BRST
B4 BK3BRST
B5 SLEWCTL1
B6 SLEWCTL2
B7 N/A
ADDRESS: 00010010
SUB-ADDRESS: 00000000
FUNCTION
Enable LDO 1
Enable LDO 2
Buck1 Burst Mode Enable
Buck2 Burst Mode Enable
Buck2 Burst Mode Enable
Buck SW Slew Rate: 00 = 1ns,
01 = 2ns, 10 = 4ns, 11 = 8ns
Not Used—No Effect On Operation
LED CONTROL
REGISTER
BIT NAME
B0 EN
B1 GR2
B2 GR1
B3 MD1
B4 MD2
B5 PWMC1
B6 PWMC2
B7 SLEWLED
ADDRESS: 00010010
SUB-ADDRESS: 00000001
FUNCTION
Enable: 1= Enable 0 = Off
Gradation GR[2:1]: 00 = 15ms, 01 = 460ms,
10 = 930ms, 11 = 1.85 Seconds
Mode MD[2:1]: 00 = CC Boost,
10 = PWM Boost, 01 = HV Boost
PWM CLK PWMC[2:1]: 00 = 8.77kHz,
01 = 4.39kHz, 10 = 2.92kHz, 11 = 2.19kHz
LED SW Slew rate: 0/1 = Fast/Slow
LED DAC REGISTER
BIT NAME
B0 DAC[0]
B1 DAC[1]
B2 DAC[2]
B3 DAC[3]
B4 DAC[4]
B5 DAC[5]
B6 N/A
B7 N/A
ADDRESS: 00010010
SUB-ADDRESS: 00000010
FUNCTION
6-Bit Log DAC Code
Not Used—No Effect On 0peration
Not Used—No Effect On 0peration
LED PWM REGISTER
BIT NAME
B0 PWMDEN[0]
B1 PWMDEN[1]
B2 PWMDEN[2]
B3 PWMDEN[3]
B4 PWMNUM[0]
B5 PWMNUM[1]
B6 PWMNUM[2]
B7 PWMNUM[3]
ADDRESS: 00010010
SUB-ADDRESS: 00000011
FUNCTION
PWM Denominator
PWM Numerator
PUSHBUTTON INTERFACE OPERATION
State Diagram/Operation
Figure 18 shows the LTC3577 pushbutton state diagram.
Upon first application of power (V_BUS, WALL or BAT) an
internal power-on reset (POR) signal places the pushbutton
circuitry into the power-down (PDN1) state. One second
after entering the PDN1 state the pushbutton circuitry will
transition into the hard reset (HR) state. The following
events cause the state machine to transition out of HR
into the power-up (PUP1) state:
1) ON input low for 400ms (PB400MS)
2) Application of external power (EXTPWR)
3) PWR_ON input going high (PWR_ON)
HR
PB400MS +
EXTPWR +
PWR_ON
PUP2
PUP1
PB400MS +
EXTPWR +
PWR_ON
5SEC 5SEC
POFF
PON
PWR_ON
1SEC _+UVLO
HRST
HRST
1SEC
PDN2
PDN1
HRST
POR
Figure 18. Pushbutton State Diagram
3577fa
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