LTC3632_15 Datasheet, PDF (3/22 Pages) Linear Technology – High Efficiency, High Voltage 20mA Synchronous Step-Down Converter

LTC3632
ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating
junction temperature range, otherwise specifications are for T_A = 25°C (Note 2). V_IN = 10V, unless otherwise noted.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
Input Supply (V_IN)
V_IN
Input Voltage Operating Range
UVLO
V_IN Undervoltage Lockout
V_IN Rising
V_IN Falling
Hysteresis
4.5
50
l 3.80
4.15
4.50
l 3.75
4.00
4.35
150
OVLO
V_IN Overvoltage Lockout
V_IN Rising
V_IN Falling
Hysteresis
54
56
59
52
54
57
2
I_Q
DC Supply Current (Note 3)
Active Mode
Sleep Mode
Shutdown Mode
Output Supply (V_FB)
V_FB
Feedback Comparator Trip Voltage
V_HYST
Feedback Comparator Hysteresis Voltage
I_FB
Feedback Pin Current
∆V_LINEREG
Feedback Voltage Line Regulation
Operation
V_RUN = 0V
V_FB Rising
V_FB = 1V
V_IN = 4.5V to 50V
l 0.792
l
3
–10
125
12
3
0.800
5
0
0.001
220
22
6
0.808
7
10
V_RUN
RUN Pin Threshold Voltage
RUN Rising
RUN Falling
Hysteresis
1.17
1.21
1.25
1.06
1.10
1.14
110
I_RUN
V_HYSTL
I_HYST
I_SS
t_INTSS
I_PEAK
R_ON
RUN Pin Leakage Current
Hysteresis Pin Voltage Low
Hysteresis Pin Leakage Current
Soft-Start Pin Pull-Up Current
Internal Soft-Start Time
Peak Current Trip Threshold
Power Switch On-Resistance
Top Switch
Bottom Switch
RUN = 1.3V
RUN < 1V, I_HYST = 1mA
V_HYST = 1.3V
V_SS < 1.5V
SS Pin Floating
I_SET Floating
500k Resistor from I_SET to GND
I_SET Shorted to GND
I_SW = –10mA
I_SW = 10mA
–10
0
10
0.07
0.1
–10
0
10
4.5
5.5
6.5
0.75
l
40
50
60
25
8
10
13
5.0
2.5
UNITS
V
V
V
mV
V
V
V
µA
µA
µA
V
mV
nA
%/V
V
V
mV
nA
V
nA
µA
ms
mA
mA
mA
Ω
Ω
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 LTC3632 is tested under pulsed load conditions such that T_J ≈ T_A.
LTC3632E is guaranteed to meet specifications from 0°C to 85°C junction
temperature. Specifications over the –40°C to 125°C operating junction
temperature range are assured by design, characterization and correlation
with statistical process controls. The LTC3632I is guaranteed over the
full –40°C to 125°C operating junction temperature range. Note that the
maximum ambient temperature consistent with these specifications is
determined by specific operating conditions in conjunction with board
layout, the rated package thermal impedance and other environmental
factors. The junction temperature (T_J, in °C) is calculated from the ambient
temperature (T_A, in °C) and power dissipation (P_D, in Watts) according to
the formula:
T_J = T_A + (P_D • θ_JA), where θ_JA (in °C/W) is the package thermal
impedance.
Note 3: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
3632fc
3