sx1511iultrt Semtech Corporation, sx1511iultrt Datasheet - Page 37

• Manufacturer Part Number: sx1511iultrt
• Description: World
• Manufacturer: Semtech Corporation

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 1 – 24
A
Typical Application Circuit
Typical LED Connection
PPLICATION
th
Feb. 2010
I
NFORMATION
controller
Host
Optional (depends
on the application)
NSS
SCK
SO
I/O
I/O
SI
Figure 19 - Typical Application Schematic
*
LED colour/technology dependent
SX1510/11/12
Figure 20 – Typical LED Operation
VCCx
3.3V
IOx
VCCx
37
IOL
VDDM
NRESET
NSS
SCK
SI
SO
SX1511
VBAT
OSCIO
World’s Lowest Voltage Level Shifting GPIO
R
GND
VLED
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
SX1510/SX1511/SX1512
2.5V
1.2V
5V
www.semtech.com
5V