ltc3858-2 Linear Technology Corporation, ltc3858-2 Datasheet - Page 3

• Manufacturer Part Number: ltc3858-2
• Description: Ltc3858-2 - Low Iq, Dual 2-phase Synchronous Step-down Controller
• Manufacturer: Linear Technology Corporation

ELECTRICAL CHARACTERISTICS
SYMBOL
V
g
I
UVLO
V
I
I
DF
I
V
V
V
Gate Driver
TG1,2
BG1,2
TG1,2 t
TG1,2 t
BG1,2 t
BG1,2 t
TG/BG t
BG/TG t
t
junction temperature range, otherwise specifications are at T
otherwise noted.
Q
SENSE
SENSE
SS1,2
ON(MIN)
m1,2
LOADREG
OVL
RUN1,2
RUN1,2
SENSE(MAX)
MAX
+
–
r
f
r
f
1D
1D
On
Hyst RUN Pin Hysteresis Voltage
PARAMETER
Output Voltage Load Regulation
Transconductance Amplifier g
Input DC Supply Current
Pulse-Skipping or Forced Continuous
Mode (One Channel On)
Pulse-Skipping 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
Maximum Current Sense
Threshold Voltage
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
TG Transition Time:
BG Transition Time:
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
Minimum On-Time
Rise Time
Fall Time
Rise Time
Fall Time
+
–
Pins Current
Pins Current
m
CONDITIONS
(Note 4)
Measured in Servo Loop,
ΔI
(Note 4)
Measured in Servo Loop,
ΔI
(Note 4) I
(Note 5)
RUN1 = 5V and RUN2 = 0V, V
RUN1 = 0V and RUN2 = 5V, V
RUN1,2 = 5V, V
RUN1 = 5V and RUN2 = 0V, V
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
V
V
(Note 6)
C
C
(Note 6)
C
C
C
C
(Note 7)
OUT1,2
OUT1,2
SS1,2
RUN1
FB1,2
FB1,2
FB1,2
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
TH
TH
CC
CC
Voltage = 1.2V to 0.7V
Voltage = 1.2V to 2V
, V
= 0.7V, V
= 0.7V, V
= 0.7V, V
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
= 0V
Ramping Up
Ramping Down
< INTV
> INTV
RUN2
TH1,2
The
Rising
FB1,2
CC
CC
= 1.2V, Sink/Source = 5μA
FB1,2
FB1,2
SENSE1
SENSE1
SENSE1
A
– 0.5V
+ 0.5V
= 25°C (Note 2). V
l
, Relative to Regulated V
denotes the specifications which apply over the full operating
= 0.83V (No Load)
= 0.83V (No Load)
–,
–,
–,
2
2
2
– = 3.3V, I
– = 3.3V, I
– = 3.3V, I
FB1
FB2
FB1
FB2
= 0.83V (No Load) or
= 0.83V (No Load)
= 0.83V (No Load) or
= 0.83V (No Load)
LIM
LIM
LIM
= 0
= FLOAT
= INTV
IN
= 12V, V
FB1,2
CC
RUN1,2
l
l
l
l
l
l
l
l
= 5V, EXTV
1.21
MIN
3.6
0.7
98
22
43
64
7
CC
LTC3858-2
= 0V unless
–0.01
0.01
1.26
TYP
170
300
550
1.3
4.0
3.8
1.0
2.5
1.5
2.4
1.1
10
99
50
30
50
75
25
16
28
13
30
30
95
2
8
2
MAX
–0.1
1.31
250
450
0.1
4.2
1.4
20
13
±1
±1
36
57
86
4
UNITS
mmho
38582f
3
mA
mA
mV
mV
mV
mV
μA
μA
μA
μA
μA
μA
μA
ns
ns
ns
ns
ns
ns
ns
%
%
%
%
Ω
Ω
Ω
Ω
V
V
V