LTC3706_15 Datasheet, PDF (4/22 Pages) Linear Technology – Secondary-Side Synchronous Forward Controller with PolyPhase Capability

LTC3706
ELECTRICAL CHARACTERISTICS The l indicates specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C. V_CC = 7V, V_IN = 15V, GND = PGND = 0V, unless otherwise noted.
SYMBOL
PARAMETER
Oscillator and Phase-Locked Loop
I_FS
f_LOW
f_HIGH
∆f (R_FS)
f_PLL(MAX)
f_PLL(MIN)
PGOOD Output
FS/SYNC Pin Sourcing Current
Oscillator Low Frequency Set Point
Oscillator High Frequency Set Point
Oscillator Resistor Set Accuracy
Maximum PLL Sync Frequency
Minimum PLL Sync Frequency
V_FBH/0.6
Power Good Upper Threshold
V_FBL1/0.6
Power Good Lower Threshold
V_FBL2/0.6
Power Good Lower Threshold
Differential Amplifier (V_SENSE AMP)
ADA
Gain
CMRR DA
Common Mode Rejection Ratio
R_IN
Input Resistance
f_BW
–3dB Bandwidth
CONDITIONS
V_FS/SYNC = GND
V_FS/SYNC = VCC
75kΩ < R_FS/SYNC < 175kΩ
V_FB Rising
V_FB Rising
V_FB Falling
V_S– = GND, 1V ≤ V_S+ ≤ 5V
MIN TYP MAX UNITS
20
µA
165
200
235
kHz
247
300
353
kHz
–22
20
%
500
kHz
75
kHz
115
117
119
%
91.5
93
94.5
%
89.5
91
92.5
%
0.990
1
1.010
V/V
75
dB
80
kΩ
3
MHz
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 LTC3706E is guaranteed to meet the performance specifica-
tions over the 0°C to 85°C operating temperature range. Specifications
over the –40°C to 85°C operating temperature range are assured by
design, characterization and correlation with statistical process controls.
The LTC3706I is guaranteed and tested over the full –40°C to 85°C
operating temperature range.
Note 3: Junction temperature T_J (in °C) is calculated from the ambient tem-
perature T_A and the average power dissipation P_D (in Watts) by the formula:
T_J = T_A + q_JA • P_D
Refer to the Applications Information section for details.
Note 4: The LTC3706 is tested in a feedback loop that servos V_FB to a
voltage near the internal 0.6V reference voltage to obtain the specified ITH
voltage (V_ITH = 1.2V).
Note 5: Operating supply current is measured in test mode. Dynamic
supply current is higher due to the internal gate charge being delivered
at the switching frequency. See the Typical Performance Characteristics
section.
3706fd
4