LTC3857IUH#TRPBF Linear Technology, LTC3857IUH#TRPBF Datasheet - Page 3

• Manufacturer Part Number: LTC3857IUH#TRPBF
• Description: IC CTRLR STP-DN SYNC DUAL 32QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3857IUH#TRPBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 24 V
• Frequency - Switching: 50kHz ~ 900kHz
• Voltage - Input: 4 ~ 38 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 32-QFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -

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
temperature range, otherwise specifications are at T
Q
SENSE
SENSE
TRACK/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
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
Maximum Current Sense Threshold
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
TG Transistion Time:
BG Transistion 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
+
–
Pin 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 , 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)
SENSE
SENSE
TRACK1,2
RUN1
FB1,2
FB1,2
FB1,2
LOAD
LOAD
LOAD
LOAD
LOAD
LOAD
TH
TH
A
CC
CC
Voltage = 1.2V to 0.7V
Voltage = 1.2V to 2V
= 25°C (Note 2). V
, V
= 0.7V, V
= 0.7V, V
= 0.7V, V
= 3300pF
= 3300pF
= 3300pF
= 3300pF
= 3300pF Each Driver
= 3300pF Each Driver
–
–
Ramping Up
Ramping Down
< INTV
> INTV
RUN2
TH1, 2
The
= 0V
Rising
FB1,2
l
CC
CC
SENSE1
SENSE1
SENSE1
= 1.2V, Sink/Source = 5μA
FB1,2
FB1,2
denotes the specifications which apply over the full operating junction
– 0.5V
+ 0.5V
, Relative to Regulated V
= 0.83V (No Load)
= 0.83V (No Load)
–,
–,
–,
2
2
2
– = 3.3V, I
– = 3.3V, I
– = 3.3V, I
IN
FB1
FB1
FB2
FB2
= 12V, V
= 0.83V(No Load) or
= 0.83V(No Load) or
= 0.83V(No Load)
= 0.83V(No Load)
LIM
LIM
LIM
RUN1,2
= 0
= FLOAT
= INTV
FB1,2
CC
= 5V, EXTV
l
l
l
l
l
l
l
l
CC
1.21
MIN
3.6
0.7
98
22
43
64
7
= 0V, unless otherwise noted.
–0.01
0.01
99.4
1.26
TYP
550
1.3
4.0
3.8
2.5
1.5
2.4
1.1
50
65
10
50
30
50
75
25
16
28
13
30
30
95
2
2
8
1
LTC3857
MAX
–0.1
1.31
120
950
0.1
4.2
1.4
75
20
13
±1
±1
36
57
85
4
UNITS
mmho
3857fc
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