fll798x0414

DC-DC converters
High performance switching
regulators for industrial
Up to 3 A and up to 61 V input voltage range step down ideal for fail safe
systems
ST’s L7985, L7986, L7987 and
ST1S14, are perfect solutions for
industrial applications and fail
safe systems.
These devices are able to
provide up to 3 A of continuous
output current and with a wide
input voltage range from 4.5 V
up to 61 V, accordingly to the
part number chosen.
High flexibility is given by
several adjustable parameters,
like output voltage, switching
frequency, current limit and soft
start to name a few.
KEY FEATURES
• High switching frequency up to 1.5 MHz
• Wide input voltage range up to 61 V
• Full set of embedded protection functions
• Extended operation junction temperature
KEY BENEFITS
• High safety margin
KEY APPLICATIONS
• Industrial application
• Fail safe systems
• Factory automation
• Building automation
• PLCs
• 24 V bus applications
• High robustness and reliability
• High design flexibility
• Low BOM cost
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BLOCK DIAGRAM
Digital I/O
Sensors
Power supply line
12 V - 24 V
Vin
DC-DC
Analog output
modules 1..
Analog output
modules #
DEVICE SUMMARY
Part Number
Package
Input voltage range (V)
L7985, L7985A
L7986, L7986A
DFN3x3 10L/ HSOP 8 DFN3x3 10L/ HSOP 8
L7986TA
ST1S14
L7987(*)
L7987L(*)
HSOP 8
HSOP 8
HTSSOP 16
HTSSOP 16
4.5 to 38
4.5 to 38
4.5 to 38
5.5 to 48
4.5 to 61
4.5 to 61
2
3
3
3
Up to 3
Up to 2
0.6 to Vin
0.6 to Vin
0.6 to Vin
0.8 to 97% Vin
0.8 to 97% Vin
0.8 to 97% Vin
Switching frequency
(kHz)
250 to 1000
250 to 1000
250 to 1000
850
250 to 1500
250 to 1500
External synchronization
frequency (kHz)
Up to 1000
Up to 1000
Up to 1000
N.A
Up to 1500
Up to 1500
Adjustable current
limit, Adjustable soft
start, Enable pin,
PGood
Adjustable current
limit, Adjustable soft
start, Enable pin,
PGood
Output current (A)
Output voltage range (V)
Additional features
Enable pin, Soft start
Enable pin, Soft start
Enable pin, Soft start
Enable/Inhibit pin,
PGood, Soft start
Operating junction
temperature (Tj °C)
-40, 150
-40, 150
-40, 150
-40, 150
-40, 150
-40, 150
25
25
-40, 125
25
25
25
Parameters tested and
guaranteed over the
temperature Tj (°C)
(*) Coming soon
© STMicroelectronics - April 2014 - Printed in United Kingdom - All rights reserved
The STMicroelectronics corporate logo is a registered trademark of the STMicroelectronics group of companies
All other names are the property of their respective owners
Order code: FLL798x0414
For more information on ST products and solutions, visit www.st.com