LT3669_15 Datasheet, PDF (1/40 Pages) Linear Technology – IO-Link Transceiver with Integrated Step-Down Regulator and LDO

FEATURES
n _IO-Link^® _{PHY Compatible (COM1/COM2/COM3)}
n _{Cable Interface Protected to ±60V}
n _{Operation from 7.5V to 40V}
n _{Integrated Step-Down Switching Regulator}
n _{Max Load Current: 100mA (LT3669)/}
300mA (LT3669-2)
n _{Synchronizable and Adjustable Switching}
Frequency: 250kHz to 2.2MHz
n _{Output Voltage: 0.8V to 16V}
n _{Integrated 150mA LDO Linear Regulator}
n _{Rugged Line Drivers with Adjustable Slew Rate and}
Current Limit
n _{Adaptive Line Driver Pulsing Scheme to Switch}
Heavy Loads Safely
n _{Drivers Configurable as Push-Pull, Pull-Up or}
Pull-Down
n _{Adjustable Power-On Reset Timer}
n _{Small 28-Pin Thermally Enhanced 4mm × 5mm}
QFN Package
APPLICATIONS
n _{Industrial Sensors and Actuators}
LT3669/LT3669-2
IO-Link Transceiver with
Integrated Step-Down
Regulator and LDO
DESCRIPTION
The LT^®3669 is an industrial transceiver that includes a
step-down switching regulator and a low dropout linear
regulator. Wake-up detect functionality, as well as a pro-
grammable power-on reset timer are also included. The
current limit and slew rate of the transmitters are externally
adjustable for optimum EMC performance.
The line drivers can source/sink up to 250mA of current
each or 500mA when connected together, with a minimal
residual voltage of less than 2.1V. An internal adaptive
pulsing scheme allows the drivers to safely switch heavy
capacitive loads and incandescent bulbs. Thermal shut-
down provides additional protection. Line protection of
±60V in the line interface pins allows the use of standard
TVS diodes with L+ operating voltages up to 40V.
The switching regulator integrates the catch diode in
LT3669 (up to 100mA load current) and requires an exter-
nal catch diode in LT3669-2 (up to 300mA load current).
The LT3669 implements an IO-Link device PHY. For IO-Link
master designs, see the LTC2874.
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and Hot Swap
is a trademark of Linear Technology Corporation. IO-Link is a registered trademark of PROFIBUS
User Organization (PNO). All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
82µH
0.1µF
RESET
I/O
I/O
µC ^I/O
I/O
I/O
I/O
I/O
I/O
LT3669
BD
FB_OUT
LDO_IN
SW
CPOR
BST
SYNC
RT
SR
ILIM
RST
LDO
SC1
FB_LDO
SC2
AGND
WAKE
RXD1
DIO
TXEN1 EN/UVLO
TXD1
L+
TXEN2
Q2
TXD2
CQ1
GND
53.6k
0.1µF 10.2k
5V
100mA
10µF
38.3k
t_RST = 12.5ms
f_SW = 600kHz
42.2k
14k
4.42k
3.3V
100mA
1µF
470pF
470pF
V_L+, 7.5V TO 40V
TRANSIENT TO 60V
250mA
250mA
4.7µF ²
1
4
3
36692 TA01a
Operating Waveforms
TXD1
5V/DIV
RXD1
5V/DIV
CQ1
5V/DIV
10µs/DIV
(RXD1 PULL-UP RESISTOR = 10k)
For more information www.linear.com/LT3669
0V
0V
0V
36692 TA01b
3669fa
1