LTC3205_15 Datasheet, PDF (3/16 Pages) Linear Technology – Multidisplay LED Controller

LTC3205
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_IN = 3.6V, DV_CC = 1.8V unless otherwise noted.
SYMBOL PARAMETER
Charge Pump (CPO)
1:1 Mode Output Impedance
2:3 Mode Output Impedance
CPO Regulation Voltage
CLK Frequency
D_IN, SCLK, LD, STEPUP, ENRGB
V_IL
Low Level Input Voltage
V_IH
High Level Input Voltage
I_IH
Input Current
I_IL
Input Current
Serial Port Timing
t_DS
D_IN Valid to SCLK Setup
t_DH
D_IN Valid to SCLK Hold
t_L
SCLK Low Time
t_H
SCLK High Time
t_LW
LD Pulse Width
t_CL
SCLK to LD
t_LC
LD to SCLK
CONDITIONS
V_IN = 3V, V_CPO = 4.2V (Note 3)
I_CPO = 20mA, 2:3 Mode
D_IN, SCLK, LD, STEPUP, ENRGB = DV_CC
D_IN, SCLK, LD, STEPUP, ENRGB = 0V
MIN TYP MAX UNITS
0.8
Ω
2.5
Ω
4.7
V
0.6
0.8
1.1
MHz
q
q 0.85 • DV_CC
q
–1
q
–1
0.15 • DV_CC
V
V
1
µA
1
µA
35
ns
35
ns
35
ns
35
ns
35
ns
35
ns
0
ns
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3205E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: 2:3 mode output impedance is defined as (1.5V_IN – V_CPO)/I_CPO.
Note 4: Based on long term current density limitations.
TYPICAL PERFOR A CE CHARACTERISTICS
LED Pin Sink Current
vs LED Pin Voltage
Input and Output
Charge Pump Noise
I_LED
3mA/DIV
(100%
SETTING)
0mA
200mV/DIV
V_IN
AC COUPLED
(20mV/DIV)
V_OUT
AC COUPLED
(50mV/DIV)
3205 G01
I_CPO = 150mA 500ns/DIV
V_IN = 3.6V
C_IN = C_CPO = 0.7µF
3205 G02
4-LED Main Panel Efficiency
vs Input Voltage
100
90
80
70
60
50
40
30
20 _{FOUR LEDs AT 15mA/LED}
10 ^{(TYP V}F ^{AT 15mA = 3.2V)}
T_A = 25°C
0
3.0
3.3
3.6
3.9
4.2
INPUT VOLTAGE (V)
3205 TA01b
3205f
3