LTC3858 Linear Technology, LTC3858 Datasheet - Page 3

• Manufacturer Part Number: LTC3858
• Description: Synchronous Step-Down Controller
• Manufacturer: Linear Technology

elecTrical characTerisTics
SYMBOL
V
g
I
UVLO
V
I
I
DF
I
V
V
V
V
I
V
Gate Driver
TG1,2
BG1,2
TG1,2 t
TG1,2 t
BG1,2 t
BG1,2 t
junction temperature range, otherwise specifications are at T
Q
SENSE
SENSE
SS1,2
DSC1,2
m1,2
LOADREG
OVL
RUN1,2
RUN1,2
SS1,2
SS1,2
SENSE(MAX)
MAX
+
–
LA
LT
LT
r
f
r
f
On
Hyst RUN Pin Hysteresis Voltage
PARAMETER
Output Voltage Load Regulation
Transconductance Amplifier g
Input DC Supply Current
Pulse Skip or Forced Continuous Mode
(One Channel On)
Pulse Skip or Forced Continuous Mode
(Both Channels On)
Sleep Mode (One Channel On)
Sleep Mode (Both Channels On)
Shutdown
Undervoltage Lockout
Feedback Overvoltage Protection
SENSE
SENSE
Maximum Duty Factor
Soft-Start Charge Current
RUN Pin On Threshold Voltage
SS Pin Latch-Off Arming Threshold Voltage V
SS Pin Latch-Off Threshold Voltage
SS Discharge Current
Maximum Current Sense Threshold Voltage V
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
TG Transistion Time:
Rise Time
Fall Time
BG Transistion Time:
Rise Time
Fall Time
+
–
Pins Current
Pins Current
m
CONDITIONS
(Note4)
Measured in Servo Loop,
∆I
(Note4)
Measured in Servo Loop,
∆I
(Note 4) I
(Note 5)
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
RUN1,2 = 5V, V
RUN1 = 5V and RUN2 = 0V or
RUN1 = 0V and RUN2 = 5V,
V
RUN1,2 = 5V, V
RUN1,2 = 0V
INTV
INTV
Measured at V
Each Channel
Each Channel
V
V
In Dropout, FREQ = 0V
V
V
V
Short-Circuit Condition V
V
V
V
(Note 6)
C
C
(Note 6)
C
C
FB1
FB1
OUT1,2
OUT1,2
SS1,2
RUN1
SS1
SS1
SS1,2
FB1,2
FB1,2
FB1,2
LOAD
LOAD
LOAD
LOAD
TH
TH
= 0.83V (No Load)
= 0.83V (No Load)
Voltage = 1.2V to 0.7V
Voltage = 1.2V to 2V
CC
CC
, V
, V
= 0.7V, V
= 0.7V, V
= 0.7V, V
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 0V
, V
= 4.5V
Ramping Up
Ramping Down
The
SS2
SS2
< INTV
> INTV
RUN2
TH1,2
A
Rising from 1V
Falling from 2V
= 25°C. V
l
Rising
= 1.2V, Sink/Source = 5µA
FB1,2
denotes the specifications which apply over the full operating
CC
CC
FB1,2
FB1,2
SENSE1
SENSE1
SENSE1
– 0.5V
+ 0.5V
, Relative to Regulated V
= 0.83V (No Load)
= 0.83V (No Load)
–,
–,
–,
IN
2
2
2
– = 3.3V, I
– = 3.3V, I
– = 3.3V, I
FB1,2
= 12V, V
= 0.5V,
RUN1,2
LIM
LIM
LIM
= 0
= FLOAT
= INTV
= 5V, EXTV
FB1,2
CC
l
l
l
l
l
l
l
l
CC
= 0V unless otherwise noted.
1.23
MIN
3.6
0.7
1.9
1.3
98
22
43
64
7
7
www.DataSheet4U.com
–0.01
0.01
99.4
1.28
TYP
170
300
540
1.3
4.0
3.8
1.0
1.5
2.5
1.5
2.4
1.1
10
50
10
30
50
75
25
16
28
13
2
2
8
2
LTC3858
MAX
–0.1
1.33
250
450
700
0.1
4.2
1.4
2.1
1.7
20
13
±1
±1
13
36
57
86
4
UNITS
mmho
3858fa

mA
mA
mV
mV
mV
mV
µA
µA
µA
µA
µA
µA
µA
µA
ns
ns
ns
ns
%
%
%
%
Ω
Ω
Ω
Ω
V
V
V
V
V