LTC3856 LINER [Linear Technology], LTC3856 Datasheet - Page 5

• Manufacturer Part Number: LTC3856
• Description: 2-Phase Synchronous Step-Down DC/DC Controller with Diffamp
• Manufacturer: LINER [Linear Technology]

elecTrical characTerisTics
SYMBOL
Differential Amplifier
A
R
V
PSRR
I
V
On-Chip Driver
TG R
TG R
BG R
BG R
GBW
SR
Stage Shedding Mode
I
AVP (Active Voltage Positioning)
V
I
I
V
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LTC3856 is tested under pulse load conditions such that
T
from 0°C to 85°C operating junction temperature. Specifications over
the –40°C to 125°C operating junction temperature range are assured by
design, characterization and correlation with statistical process controls.
The LTC3856I is guaranteed to meet performance specifications over the
full –40°C to 125°C operating junction temperature range.
Note 3: T
dissipation, P
junction temperature range, otherwise specifications are at T
CL
ISET
SINK
SOURCE
AVP
AVP
J
DA
OS
OUT(MAX)
IN
≈
LTC3856UH: T
LTC3856FE: T
-V
UP
DOWN
UP
DOWN
T
A
O(MAX)
. The LTC3856E is guaranteed to meet performance specifications
J
is calculated from the ambient temperature, T
D
, according to the following formula:
PARAMETER
Gain
Input Resistance
Input Offset Voltage
Power Supply Rejection Ratio
Maximum Output Current
Maximum Output Voltage
TG Pull-Up R
TG Pull-Down R
BG Pull-Up R
BG Pull-Down R
Gain-Bandwidth Product
Slew Rate
Programmable Stage Shedding
Mode Current
Maximum V
Sink Current of AVP Pin
Source Current of AVP Pin
Maximum Voltage Drop V
J
J
= T
= T
A
A
+ (P
+ (P
OUT
DS(ON)
D
DS(ON)
D
• 25°C/W)
• 34°C/W)
DS(ON)
with AVP
DS(ON)
AVP
to V
O
A
CONDITIONS
E-Grade
I-Grade
Measured at DIFFP Input
V
4.5V < V
I
TG High
TG Low
BG High
BG Low
(Note 8)
(Note 8)
SENSE
SENSE
SENSE
, and power
DIFFOUT
DIFFP
= V
+
+
+
= 300µA
IN
= 1.2V
= 1.2V
= 1.2V
DIFFOUT
< 38V
The
A
= 25°C (Note 2). V
l
= 1.5V, I
denotes the specifications which apply over the full operating
Note 4: The LTC3856 is tested in a feedback loop that servos V
specified voltage and measures the resultant V
Note 5: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See the Applications Information
section.
Note 6: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels.
Note 7: The minimum on-time condition corresponds to the on inductor
peak-to-peak ripple current ≥40% of I
Considerations in the Applications Information section).
Note 8: Guaranteed by design.
DIFFOUT
= 100µA
IN
= 15V, V
RUN
= 5V, unless otherwise noted.
l
l
MAX
V
0.998
0.997
INTVCC
–1.4
(see Minimum On-Time
MIN
6.5
2
FB
.
V
INTVCC
–1.1
TYP
LTC3856
100
250
120
2.6
1.5
2.4
1.1
7.5
2.5
80
1
1
3
3
2
2
1.002
1.003
MAX
8.5
2
ITH
to a
UNITS

3856f
MHz
V/µs
V/V
V/V
mV
mA
mA
mV
kΩ
dB
µA
µA
Ω
Ω
Ω
Ω
V
V