LTC3717 Datasheet, PDF (3/20 Pages) Linear Technology – Wide Operating Range, No RSENSE Step-Down Controller for DDR/QDR Memory Termination

LTC3717
ELECTRICAL CHARACTERISTICS _{The q denotes specifications which apply over the full operating}
temperature range, otherwise specifications are T_A = 25°C. V_CC = 15V unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX UNITS
V_CC(UVLO)
Undervoltage Lockout Threshold
V_CC Falling
q
3.4
3.9
V
V_CC(UVLOR)
Undervoltage Lockout Threshold
V_CC Rising
q
3.5
4
V
TG R_UP
TG R_DOWN
TG Driver Pull-Up On Resistance
TG Driver Pull-Down On Resistance
TG High
TG Low
2
3
Ω
2
3
Ω
BG R_UP
BG Driver Pull-Up On Resistance
BG High
3
4
Ω
BG R_DOWN
TG t_r
BG Driver Pull-Down On Resistance
TG Rise Time
BG Low
C_LOAD = 3300pF
1
2
Ω
20
ns
TG t_f
TG Fall Time
C_LOAD = 3300pF
20
ns
BG t_r
BG Rise Time
C_LOAD = 3300pF
20
ns
BG t_f
BG Fall Time
Internal V_CC Regulator
C_LOAD = 3300pF
20
ns
V_INTVCC
Internal V_CC Voltage
6V < V_CC < 30V, V_EXTVCC = 4V
q 4.7
5
5.3
V
∆V_LDO(LOADREG) Internal V_CC Load Regulation
V_EXTVCC
EXTV_CC Switchover Voltage
I_CC = 0mA to 20mA, V_EXTVCC = 4V
I_CC = 20mA, V_EXTVCC Rising
– 0.1
±2
%
q 4.5
4.7
V
∆V_EXTVCC
EXTV_CC Switch Drop Voltage
I_CC = 20mA, V_EXTVCC = 5V
150 300
mV
∆V_EXTVCC(HYS) EXTV_CC Switchover Hysteresis
PGOOD Output
200
mV
∆V_FBH
PGOOD Upper Threshold
V_FB Rising (0% = 1/3 V_REF)
8
10
12
%
∆V_FBL
∆V_FB(HYS)
PGOOD Lower Threshold
PGOOD Hysteresis
V_FB Falling (0% = 1/3 V_REF)
V_FB Returning (0% = 1/3 V_REF)
–8
– 10 – 12
%
1
2
%
V_PGL
PGOOD Low Voltage
I_PGOOD = 5mA
0.15
0.4
V
Note 1: Absolute Maximum Ratings are those values beyond which the life of
a device may be impaired.
Note 2: T_J is calculated from the ambient temperature T_A and power
dissipation P_D as follows:
LTC3717EGN: T_J = T_A + (P_D • 130°C/W)
Note 3: The LTC3717 is tested in a feedback loop that adjusts V_FB to achieve
a specified error amplifier output voltage (I_TH).
Note 4: The LTC3717E 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.
sn3717 3717fs
3