LTC3721-2 LINER [Linear Technology], LTC3721-2 Datasheet - Page 3

• Manufacturer Part Number: LTC3721-2
• Description: Synchronous Rectifier Driver for Forward Converters
• Manufacturer: LINER [Linear Technology]

SYMBOL
t
V
Current Sense
I
I
V
V
SYNC Input
I
V
V
Driver Output
R
R
I
Switching Characteristics (Note 7)
t
t
t
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 LTC3900 is tested under pulsed 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 LTC3900I is guaranteed over the –40°C to 125°C operating
junction temperature range. The LTC3900H is guaranteed over the full
–40°C to 150°C operating junction temperature range. The LTC3900MP
is guaranteed and tested over the full –55°C to 150°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes; operating lifetime is derated for junction temperatures greater
than 125°C. Note that the maximum ambient temperature consistent
with these specifications is determined by specific operating conditions
in conjunction with board layout, the rated package thermal impedance
and other environmental factors. The junction temperature (T
elecTrical characTerisTics
junction temperature range, otherwise specifications are at T
TMRDIS
CS
CS
SYNC
PK
d
SYNC
r
J
TMRMAX
CSMAX
CS
SYNCP
SYNCN
ONH
ONL
, t
≈
+
–
f
T
A
. The LTC3900E is guaranteed to meet performance specifications
PARAMETER
Timer Discharge Time
Timer Pin Clamp Voltage
CS
CS
CS
Current Sense Threshold Voltage
SYNC Input Current
SYNC Input Positive Threshold
SYNC Positive Input Hysteresis
SYNC Input Negative Threshold
SYNC Negative Input Hysteresis
Driver Pull-Up Resistance
Driver Pull-Down Resistance
Driver Peak Output Current
SYNC Input to Driver Output Delay
Minimum SYNC Pulse Width
Driver Rise/Fall Time
+
+
–
Input Current
Pin Clamp Voltage
Input Current
CONDITIONS
C
C
V
V
I
V
LTC3900E/LTC3900I (Note 5)
LTC3900H/LTC3900MP (Note 5)
V
(Note 6)
(Note 6)
I
LTC3900E/LTC3900I
LTC3900H/LTC3900MP
I
LTC3900E/LTC3900I
LTC3900H/LTC3900MP
(Note 6)
C
LTC3900E/LTC3900I
LTC3900H/LTC3900MP
V
C
J
IN
OUT
OUT
, in °C) is
TMR
TMR
CS
CS
CS
SYNC
FG
SYNC
FG
= 5mA, V
+ = 0V
– = 0V
– = 0V
= C
= C
= –100mA
= 100mA
= 1000pF, R
= 1000pF, R
= ±10V
= ±5V
The
CG
CG
A
= 4700pF, V
= 4700pF, V
= 25°C. V
l
SYNC
denotes the specifications which apply over the specified operating
= –5V
TMR
TMR
calculated from the ambient temperature (T
(P
Note 3: All currents into device pins are positive; all currents out of device
pins are negative. All voltages are referenced to ground unless otherwise
specified.
Note 4: Supply current in normal operation is dominated by the current
needed to charge and discharge the external MOSFET gates. This current
will vary with supply voltage, switching frequency and the external
MOSFETs used.
Note 5: The current sense comparator threshold has a 0.33%/°C
temperature coefficient (TC) to match the TC of the external MOSFET
R
Note 6: Guaranteed by design, not subject to test.
Note 7: Rise and fall times are measured using 10% and 90% levels. Delay
times are measured from ±1.4V at SYNC input to 20%/80% levels at the
driver output.
DS(ON)
D
= 4.7k
SYNC
SYNC
CC
, in watts) according to the formula:
T
impedance.
= 4.7k
J
= T
= 5V unless otherwise specified. (Notes 2, 3)
.
= ±5V
= ±5V
A
+ (P
D
• θ
JA
), where θ
l
l
l
l
l
l
l
l
l
l
l
l
l
l
l
JA
(in °C/W) is the package thermal
MIN
–1.8
7.5
1.0
75
3
1
A
, in °C) and power dissipation
10.5
TYP
–1.4
2.5
1.4
0.2
0.2
0.9
0.9
40
60
11
±1
15
2
LTC3900
MAX
13.5
–1.0
120
±10
120
150
2.0
2.0
1.8
1.2
1.6
1.2
1.6
20
±1
±1
18
UNITS
3900fb
3
mV
mV
mV
µA
µA
µA
ns
ns
ns
ns
ns
Ω
Ω
Ω
Ω
Ω
Ω
V
V
V
V
V
V
A