Datasheet
LM2717
www.ti.com
SNVS253D –MAY 2005–REVISED MARCH 2013
Electrical Characteristics (continued)
Specifications in standard type face are for T
J
= 25°C and those with boldface type apply over the full Operating
Temperature Range (T
J
= −40°C to +125°C). V
IN
= 5V, I
L
= 0A, and F
SW
= 300kHz unless otherwise specified.
Symbol Parameter Conditions Min
(1)
Typ
(2)
Max
(1)
Units
I
CL1
(3)
Fixed Buck Switch Current V
IN
= 8V
(4)
2.2 A
Limit
I
CL2
(3)
Adjustable Buck Switch V
IN
= 8V
(4)
3.2 A
Current Limit
I
B1
Fixed Buck FB Pin Bias V
IN
= 20V
65 µA
Current
(5)
I
B2
Adjustable Buck FB Pin Bias V
IN
= 20V
65 nA
Current
(5)
V
IN
Input Voltage Range 4 20 V
g
m1
Fixed Buck Error Amp ΔI = 20µA
1340 µmho
Transconductance
g
m2
Adjustable Buck Error Amp ΔI = 20µA
1360 µmho
Transconductance
A
V1
Fixed Buck Error Amp Voltage
134 V/V
Gain
A
V2
Adjustable Buck Error Amp
136 V/V
Voltage Gain
D
MAX
Maximum Duty Cycle 89 93 %
F
SW
Switching Frequency R
F
= 46.4k 200 300 400 kHz
R
F
= 22.6k 475 600 775 kHz
I
SHDN1
Fixed Buck Shutdown Pin 0V < V
SHDN1
< 7.5V
−5 5 µA
Current
I
SHDN2
Adjustable Buck Shutdown Pin 0V < V
SHDN2
< 7.5V
−5 5 µA
Current
I
L1
Fixed Buck Switch Leakage V
IN
= 20V
0.01 5 µA
Current
I
L2
Adjustable Buck Switch V
IN
= 20V
0.01 5 µA
Leakage Current
R
DSON1
Fixed Buck Switch R
DSON
(6)
160 mΩ
R
DSON2
Adjustable Buck Switch
160 mΩ
R
DSON
(6)
Th
SHDN1
Fixed Buck SHDN Threshold Output High 1.8 1.36
V
Output Low 1.33 0.7
Th
SHDN2
Adjustable Buck SHDN Output High 1.8 1.36
V
Threshold
Output Low 1.33 0.7
I
SS1
Fixed Buck Soft Start Pin
4 9 15 µA
Current
I
SS2
Adjustable Buck Soft Start Pin
4 9 15 µA
Current
UVP On Threshold 4 3.8
V
Off Threshold 3.6 3.3
θ
JA
Thermal Resistance
(7)
TSSOP, package only 115 °C/W
(3) Duty cycle affects current limit due to ramp generator.
(4) Current limit at 0% duty cycle. See TYPICAL PERFORMANCE section for Switch Current Limit vs. V
IN
(5) Bias current flows into FB pin.
(6) Includes the bond wires, R
DSON
from V
IN
pin(s) to SW pin.
(7) Refer to Texas Instruments packaging website for more detailed thermal information and mounting techniques for the TSSOP package.
Copyright © 2005–2013, Texas Instruments Incorporated Submit Documentation Feedback 5
Product Folder Links: LM2717