LTC3770_15 Datasheet, PDF (4/24 Pages) Linear Technology – Fast No RSENSE Step-Down Synchronous Controller with Margining, Tracking and PLL

LTC3770
ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating
temperature range, otherwise specifications are T_A = 25°C. V_IN = 15V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
Internal V_CC Regulator
V_INTVCC
Internal V_CC Voltage
ΔV_LDO(LOADREG) Internal V_CC Load Regulation
Phased-Locked Loop
6V < V_IN < 30V
I_CC = 0mA to 20mA
l 4.7
5
5.3
V
– 0.1
±2
%
R_PLLIN
I_PLLFLTR
PGOOD Output
PLLIN Input Resistance
Phase Detector Output Current
Sink Capability
Source Capability
f_PLLIN < f₀
f_PLLIN > f₀
50
kΩ
–15
μA
15
μA
ΔV_FBH
ΔV_FBL
ΔV_FB(HYS)
V_PGL
PGOOD Upper Threshold
PGOOD Lower Threshold
PGOOD Hysteresis
PGOOD Low Voltage
V_FB Rising
V_FB Falling
V_FB Returning
I_PGOOD = 5mA
7
10
13
%
–7
–10
–13
%
1.5
3
%
0.15
0.4
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: T_J is calculated from the ambient temperature T_A and power
dissipation P_D as follows:
LTC3770EG: T_J = T_A + (P_D • 130°C/W)
LTC3770EUH: T_J = T_A + (P_D • 34°C/W)
Note 3: The 3770 is tested in a feedback loop that adjusts V_FB to
achieve a specified error amplifier output voltage (I_TH). For these tests,
V_REFOUT = V_REFIN.
Note 4: The LTC3770E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 5: The minimum off-time condition is specified for large peak-to-peak
inductor ripple current (see Minimum Off-Time Considerations in
the Applications Information section).
TYPICAL PERFORMANCE CHARACTERISTICS
Current Sense Threshold
vs I_TH Voltage
300
V_RNG = ^2V
200
1.4V
1V
100
0.7V
0.5V
0
–100
On-Time vs I_ON Current
10000
V_VON = 0V
1000
100
–200
0
0.5 1.0 1.5 2.0
I_TH VOLTAGE (V)
2.5 3.0
3770 G01
10
1
10
I_ON CURRENT (μA)
100
3770 G02
On-Time vs V_ON Voltage
1200 _{IION = 60μA}
1000
800
600
400
200
0
0
1
2
3
4
5
V_ON VOLTAGE (V)
3770 G03
3770fc
4