LTC3609 Datasheet, PDF (4/24 Pages) Linear Technology – 32V, 6A Monolithic Synchronous Step-Down DC/DC Converter

LTC3609
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are at 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
V_EXTVCC
EXTV_CC Switchover Voltage
ΔV_EXTVCC
EXTV_CC Switch Drop Voltage
ΔV_EXTVCC(HYS)
EXTV_CC Switchover Hysteresis
PGOOD Output
6V < V_IN < 30V, V_EXTVCC = 4V
I_CC = 0mA to 20mA, V_EXTVCC = 4V
I_CC = 20mA, V_EXTVCC Rising
I_CC = 20mA, V_EXTVCC = 5V
l 4.7
5
5.5
V
–0.1
±2
%
l 4.5
4.7
V
150
300
mV
500
mV
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
2.5
%
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:
T_J = T_A + (P_D • 29°C/W)
(θ_JA is simulated per JESD51-7 high effective thermal conductivity
test board).
θ_JC = 1°C/W
(θ_JC is simulated when heat sink is applied at the bottom of the package).
Note 3: The LTC3609 is tested in a feedback loop that adjusts V_FB to
achieve a specified error amplifier output voltage (I_TH). The specification at
85°C is not tested in production. This specification is assured by design,
characterization, and correlation to testing at 125°C.
Note 4: The LTC3609E is guaranteed to meet performance specifications
from 0°C to 125°C. Specifications over the –40°C to 125°C operating
junction temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3609I is guaranteed
over the –40°C to 125°C operating junction temperature range.
TYPICAL PERFORMANCE CHARACTERISTICS
Transient Response
Transient Response
(Discontinuous Mode)
Start-Up
V_OUT
200mV/DIV
I_L
5A/DIV
I_LOAD
5A/DIV
20μs/DIV
LOAD STEP 0A TO 5A
V_IN = 25V
V_OUT = 2.5V
FCB = 0V
FIGURE 6 CIRCUIT
V_OUT
200mV/DIV
3609 G01
I_L
5A/DIV
I_LOAD
5A/DIV
20μs/DIV
LOAD STEP 1A TO 6A
V_IN = 25V
V_OUT = 2.5V
FCB = INTV_CC
FIGURE 6 CIRCUIT
RUN/SS
2V/DIV
3609 G02
V_OUT
1V/DIV
I_L
5A/DIV
40ms/DIV
V_IN = 12V
V_OUT = 2.5V
R_LOAD = 0.5Ω
FIGURE 6 CIRCUIT
3609 G03
3609f
4