MAX6946/MAX6947
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
4 _______________________________________________________________________________________
TIMING CHARACTERISTICS (Figure 8)
(V
DD
= 2.25V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 3.3V, T
A
= +25°C.) (Note 1)
SYMBOL
MIN TYP MAX
16-pin TQFN 23 32 42
Internal PWM Clock Frequency f
INT
16-bump WLP 20 32 45
External PWM Clock Frequency f
OSC
100
Serial-Clock Frequency f
SCL
400
Bus Free Time Between a STOP and
a START Condition
t
BUF
1.3 µs
Hold Time, (Repeated) START
Condition
t
HD
STA
0.6 µs
Repeated START Condition Setup
Time
t
SU
STA
0.6 µs
STOP Condition Setup Time
t
SU
STO
t
HD
DAT
(Note 3) 0.9 µs
Data Setup Time
t
SU
DAT
180 ns
SCL Clock Low Period t
LOW
1.3 µs
SCL Clock High Period t
HIGH
0.7 µs
Rise Time of Both SDA and SCL
Signals, Receiving
t
R
(Notes 4, 5)
20
+ 0.1C
b
300 ns
Fall Time of Both SDA and SCL
Signals, Receiving
t
F
(Notes 4, 5)
20
+ 0.1C
b
300 ns
Fall Time of SDA Transmitting t
F, TX
(Notes 4, 6)
20
+ 0.1C
b
250 ns
Pulse Width of Spike Supressed t
SP
(Note 7) 50 ns
Capacitive Load for Each Bus Line C
b
(Note 4) 400 pF
RST Pulse Width t
W
0.1 µs
16-pin TQFN 3.0
RST Rising Edge to
MAX6946/MAX6947 ACK to Cancel
Reset Run
t
RSTRUN
Reset Run enabled,
internal oscillator
enabled
16-bump WLP 2.5
RST Rising Edge to
MAX6946/MAX6947 ACK to Ensure
Reset Run
t
RSTRUN
Reset Run enabled, internal oscillator
enabled
5.6
Note 1: All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2: Port current is factory trimmed to meet a median sink current of 20mA and 10mA over all ports. The ΔI
OUT
specification
guarantees current matching between parts.
Note 3: A master device must provide a hold time of at least 300ns for the SDA signal (referred to V
IL
of the SCL signal) in order to
bridge the undefined region of SCL’s falling edge.
Note 4: Not production tested. Guaranteed by design.
Note 5: C
b
= total capacitance of one bus line in picoFarads; t
R
and t
F
are measured between 0.3 x V
DD
and 0.7 x V
DD
.
Note 6: I
SINK
≤ 6mA.
Note 7: Guaranteed by design. Input filters on the SDA and SCL inputs suppress noise spikes of less than 50ns.
