LTC3207-1_15 Datasheet, PDF (7/20 Pages) Linear Technology – 600mA Universal Multi-Output LED/CAM Driver

LTC3207/LTC3207-1
PIN FUNCTIONS
CAMHL (Pin 8): Selects CAM high register when asserted
high and CAM low register when low. The high to low
transition automatically resets the charge pump mode to
1x. The logic level for CAMHL is referenced to DV_CC. If
unused, the pin should be connected to ground.
DV_CC (Pin 9): Supply Voltage for All Digital I/O Lines. This
pin sets the logic reference level of the device. DV_CC will
reset the data registers when set below the undervoltage
lockout threshold which is the recommended method for
resetting the part after power up. A 0.1µF X5R or X7R
ceramic capacitor should be connected to ground.
SCL (Pin 10): I²C Clock Input. The logic-level for SCL is
referenced to DV_CC.
SDA (Pin 11): Input Data for the Serial Port. Serial data
is shifted in one bit per clock to control the device. The
logic-level is referenced to DV_CC.
C1P, C2P, C1M, C2M (Pin 24, 23, 20, 19): Charge Pump
Flying Capacitor Pins. A 2.2µF X7R or X5R ceramic ca-
pacitor should be connected from C1P to C1M and C2P
to C2M.
V_BAT (Pin 21): Supply Voltage for the Entire Device. This
pin must be bypassed with a single 2.2µF low ESR ceramic
capacitor.
ENU (Pin 22): Input. Used to enable or disable the prese-
lected ULED outputs. When the pin is toggled from low
(disable) to high (enable), the device illuminates the prese-
lected LEDs. When ENU is controlling selected outputs and
other outputs have been enabled the charge pump mode
will be reset to 1x on the falling edge of ENU. When ENU
is controlling selected outputs and no other outputs are
active the part will go from enabled to shutdown. The ENU
logic-level is referenced to DV_CC. This pin is connected to
ground if unused.
Exposed Pad (Pin 25): Ground. The Exposed Pad must
be soldered to PCB ground.
BLOCK DIAGRAM
V_BAT
21
DV_CC
9
ENU
22
CAMHL
8
SDA
11
SCL
10
850kHz
OSCILLATOR
19
20
23
24
C2M C1M C2P C1P
CHARGE PUMP
GND
25
CPO
1
1.22V
CONTROL
LOGIC
MASTER/SLAVE
REG
SHIFT REGISTER
12
12 UNIVERSAL
CURRENT SOURCES
AND DACS
ULED1
2
ULED2
3
ULED3
4
ULED4
5
ULED5
6
ULED6
12
ULED7
13
ULED8
14
CAM CURRENT
SOURCE
2 SECOND
SAFETY TIMER
CAM ULED12 ULED11 ULED10 ULED9
7
18
17
16
15
3207 BD
3207fc
7