LTC3901_15 Datasheet, PDF (3/16 Pages) Linear Technology – Secondary Side Synchronous Driver for Push-Pull and Full-Bridge Converters

LTC3901
ELECTRICAL CHARACTERISTICS The ● denotes specifications which apply over the full operating
temperature range. V_CC = 5V, T_A = 25°C unless otherwise specified. (Note 3)
SYMBOL
PARAMETER
Switching Characteristics (Note 8)
t_d
SYNC Input to Driver Output Delay
t_r, t_f
Driver Rise/Fall Time
CONDITIONS
C_ME = C_MF = 4700pF, V_SYNC = ±5V
C_ME = C_MF = 4700pF, V_SYNC = ±5V
MIN TYP MAX UNITS
●
60
120
ns
15
ns
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LTC3901E is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design; characterization and correlation
with statistical process controls.
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: Both CSE⁺, CSE^– and CSF⁺, CSF^– current sense comparators have
the same performance specifications.
Note 6: The current sense comparator threshold has a 0.33%/°C
temperature coefficient (TC) to match the TC of the external MOSFET
R_DSON.
Note 7: Guaranteed by design, not subject to test.
Note 8: 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.
TYPICAL PERFOR A CE CHARACTERISTICS
Timeout vs V_CC
5.25
5.20
T_A = 25°C
R_TMR = 51k
5.15 ^{CTMR = 470pF}
5.10
5.05
5.00
4.95
4.90
4.85
4.80
4.75
45 6 78
9 10 11
V_CC (V)
3901 G01
Current Sense Threshold vs
Temperature
18
17 V_CC = 5V, 11V
16
15
14
13
12
11
10
9
8
7
6
5
4
3
–50 –25 0 25 50 75 100 125
TEMPERATURE (°C)
3901 G04
Timeout vs Temperature
5.25
5.20
V_CC = 5V
R_TMR = 51k
5.15 ^{CTMR = 470pF}
5.10
5.05
5.00
4.95
4.90
4.85
4.80
4.75
–50 –25
0 25 50 75 100 125
TEMPERATURE (°C)
3901 G02
V_CS(MAX) Clamp Voltage vs CS⁺
Input Current
18
T_A = 25°C
17
16
15
14
13
12
11
10
0
5 10 15 20 25 30
CS⁺ INPUT CURRENT (mA)
3901 G05
Timeout vs R_TMR
10
T_A = 25°C
9 V_CC = 5V
8 ^{CTMR = 470pF}
7
6
5
4
3
2
1
0
0 10 20 30 40 50 60 70 80 90 100
R_TMR (kΩ)
3901 G03
SYNC Positive Threshold vs
Temperature
1.8
1.7
1.6
1.5
V_CC = 11V
1.4
V_CC = 5V
1.3
1.2
1.1
1.0
–50 –25
0 25 50 75
TEMPERATURE (°C)
100 125
3901 G06
3901f
3