Datasheet

LTC3838-1
3
38381f
For more information www.linear.com3838-1
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the specified operating
junction temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V unless otherwise noted (Note 3).
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Main Control Loops
V
IN
Input Voltage Operating Range 4.5 38 V
V
OUT1,2
Regulated Output Voltage Operating Range V
OUT1
Regulated Differentially with
Respect to V
OUTSENSE1
–
, V
OUT2
Regulated
Differentially with Respect to V
DFB2
–
0.6 5.5 V
I
Q
Input DC Supply Current
Both Channels Enabled
Only One Channel Enabled
Shutdown Supply Current
MODE/PLLIN = 0V, No Load
RUN1 or RUN2 (But Not Both) = 0V
RUN1 = RUN2 = 0V
3
2
15
mA
mA
µA
V
FB1
Regulated Feedback Voltage on Channel 1
(V
OUTSENSE1
+
– V
OUTSENSE1
–
)
ITH1 = 1.2V, V
OUTSENSE1
–
= 0V (Note 5)
T
A
= 25°C
T
A
= 0°C to 85°C
T
A
= –40°C to 125°C
l
l
0.5985
0.596
0.594
0.6
0.6
0.6
0.6015
0.604
0.606
V
V
V
Regulated Feedback Voltage on Channel 1 Over
Line, Load and Common Mode
V
IN
= 4.5V to 38V, ITH1 = 0.5V to 1.9V,
–0.5V < V
OUTSENSE1
–
< 0.5V (Note 5)
T
A
= 0°C to 85°C
T
A
= –40°C to 125°C
–0.2V < V
OUTSENSE1
–
< 0.2V
T
A
= 0°C to 85°C
T
A
= –40°C to 125°C
l
l
l
l
0.594
0.591
0.5955
0.594
0.6
0.6
0.6
0.6
0.606
0.609
0.6045
0.606
V
V
V
V
V
FB2
Regulated Feedback Voltage on Channel 2
(2 • V
DFB2
+
– V
DFB2
–
)
ITH2 = 1.2V, V
DFB2
–
= 0V (Note 5)
T
A
= 25°C
T
A
= 0°C to 85°C
T
A
= –40°C to 125°C
l
l
0.598
0.5955
0.594
0.6
0.6
0.6
0.602
0.6045
0.606
V
V
V
Regulated Feedback Voltage on Channel 2 Over
Line, Load and Common Mode
V
IN
= 4.5V to 38V, ITH2 = 0.5V to 1.9V,
–0.2V < V
DFB2
–
< 0.2V (Note 5)
T
A
= 0°C to 85°C
T
A
= –40°C to 125°C
l
l
0.5955
0.594
0.6
0.6
0.6045
0.606
V
V
I
VOUTSENSE1
+
V
OUTSENSE1
+
Input Bias Current V
OUTSENSE1
+
= 0.6V, V
OUTSENSE1
–
= 0V 0 ±25 nA
I
VOUTSENSE1
–
V
OUTSENSE1
–
Input Bias Current V
OUTSENSE1
+
= 0.6V, V
OUTSENSE1
–
= 0V –25 –50 µA
I
VDFB2
+
V
DFB2
+
Input Bias Current V
DFB2
+
= 0.3V, V
DFB2
–
= 0V 0 ±25 nA
I
VDFB2
–
V
DFB2
–
Input Bias Current V
DFB2
+
= 0.3V, V
DFB2
–
= 0V –6 –12 µA
g
m(EA)1,2
Error Amplifier Transconductance (∆I
TH1,2
/∆V
FB1,2
) ITH = 1.2V (Note 5) 1.7 mS
t
ON(MIN)1,2
Minimum Top Gate On-Time V
IN
= 38V, V
OUT
= 0.6V, R
T
= 20k (Note 6) 30 ns
t
OFF(MIN)1,2
Minimum Top Gate Off-Time (Note 6) 90 ns
Current Sensing
V
SENSE(MAX)1,2
Maximum Valley Current Sense Threshold
(V
SENSE1,2
+
– V
SENSE1,2
–
)
V
RNG
= 0V, V
FB
= 0.57V, V
SENSE
–
= 2.5V
V
RNG
= INTV
CC
, V
FB
= 0.57V, V
SENSE
–
= 2.5V
l
l
24
54
30
61
36
69
mV
mV
V
SENSE(MIN)1,2
Minimum Valley Current Sense Threshold
(V
SENSE1,2
+
– V
SENSE1,2
–
)
(Forced Continuous Mode)
V
RNG
= 0V, V
FB
= 0.63V, V
SENSE
–
= 2.5V
V
RNG
= INTV
CC
, V
FB
= 0.63V, V
SENSE
–
= 2.5V
–15
–30
mV
mV
I
SENSE1,2
+
SENSE1,2
+
Pins Input Bias Current V
SENSE
+
= 0.6V
V
SENSE
+
= 5V
±5
1
±50
±2
nA
µA
I
SENSE1,2
–
SENSE1,2
–
Pins Input Bias Current (Internal 500k
Resistor to SGND)
V
SENSE
–
= 0.6V
V
SENSE
–
= 5V
1.2
10
µA
µA