CAT9532_16 Datasheet, PDF (10/14 Pages) ON Semiconductor – 16-bit Programmable LED Dimmer

CAT9532
External Reset Operation
The CAT9532 registers and the I²C state machine are
initialized to their default state when the RESET input is
held low for a minimum of t_W. The external Reset timing is
shown in Figure 13.
LED Output Operation
Figure 11 shows typical current values for LED pin
voltages at various case temperatures.
30
VCC = 5 V
25
Power−On Reset Operation
The CAT9532 incorporates Power−On Reset (POR)
circuitry which protects the internal logic against powering
up in the wrong state. The device is in a reset state for V_CC
less than the internal POR threshold level (V_POR). When
V_CC exceeds the V_POR level, the reset state is released and
the CAT9532 internal state machine and registers are
initialized to their default state.
20
T = −45°C
15
T = 25°C
10
T = 90°C
5
0
0
100
200
300
400
VOL (mV)
Figure 11. IOL vs VOL for LED Pin
Slave Address
Data From Port
Data From Port
SDA
S 1 1 0 0 A2 A1 A0
A
DATA 1
Start Condition
R/W
Acknowledge
From Slave
READ FROM
PORT
A
DATA 4
NA P
Acknowledge
From Master
No Acknowledge
From Master ^Stop
Condition
DATA INTO
PORT
DATA 1
DATA 2
DATA 3
t_ph
t_ps
Figure 12. Read Input Port Register Timing Diagram
DATA 4
START
SCL
ACK OR READ CYCLE
SDA
30%
RESET
50%
t_REC
LEDx
t_RESET
50%
50%
t_W
t_RESET
50% _{LED OFF}
Figure 13. RESET Timing Diagram
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