SX1509BIULTRT Semtech, SX1509BIULTRT Datasheet - Page 36

• Manufacturer Part Number: SX1509BIULTRT
• Description: 16-chan GPIO W/ LED Driver & Keypad Engine (I2C)
• Manufacturer: Semtech

ADVANCED COMMUNICATIONS & SENSING
6
6.1
6.2
Typical LED Connection is described below. The LED is usually connected to a high voltage (VBAT) to take
advantage of the high sink current of the I/O and to accommodate high LED threshold voltages (VLED).
Please note that in this configuration the IO must be programmed as open drain output (RegOpenDrain) with no
pull-up (RegPullUp) and input buffer must be disabled (RegInputBufferDisable).
VCCx can take any value without compromising LED operation.
Serial R must be calculated for IOL not to exceed its max spec (Cf. Table 5) else VOL will increase.
Rev 3 – 9
A
Typical Application Circuit
Typical LED Connection
PPLICATION
th
Sept. 2010
I
NFORMATION
controller
Host
Optional (depends
on the application)
SDA
SCL
I/O
I/O
Figure 21 - Typical Application Schematic
*
LED colour/technology dependent
Figure 22 – Typical LED Operation
SX1507/8/9B
VCCx
3.3V
IOx
VCCx
36
IOL
VDDM
NRESET
SCL
SDA
ADDR1
ADDR0
SX1508B
VBAT
OSCIO
World’s Lowest Voltage Level Shifting GPIO
R
GND
VLED
SX1507B/SX1508B/SX1509B
VCC1
VCC2
I/O[0]
I/O[1]
I/O[4]
I/O[5]
I/O[6]
I/O[7]
I/O[2]
I/O[3]
NINT
*
with LED Driver and Keypad Engine
2.5V
1.2V
5V
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5V