Datasheet

LT3694/LT3694-1
3
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ELECTRICAL CHARACTERISTICS
PARAMETER CONDITIONS MIN TYP MAX UNITS
V
IN
Internal Undervoltage Lockout
l
3.5 3.8 4 V
Overvoltage Shutdown Threshold
l
36 38 40 V
Input Quiescent Current Not Switching 1 2 mA
Bias Quiescent Current Not Switching 2 3.5 mA
Shutdown Current V
EN/UVLO
= 0.1V 0.1 2 µA
EN/UVLO Threshold, Bias On 350 500 mV
EN/UVLO Threshold, Switching On
l
1.16 1.2 1.23 V
Reference Voltage Line Regulation 5V < V
IN
< 36V 0.01 %/V
Switching Frequency R
T
= 40.2k
l
0.9 1.0 1.1 MHz
SYNC Input Frequency Range LT3694 Only
l
0.25 2.5 MHz
V
IH
, SYNC LT3694 Only
l
1.5 V
V
IL
, SYNC LT3694 Only
l
0.35 V
V
OH
, CLKOUT I
CLKOUT
= –50µA, LT3694-1 Only
l
1.6 2.6 V
V
OL
, CLKOUT I
CLKOUT
= 50µA, LT3694-1 Only
l
0.3 V
PGOOD Output Voltage Low I
PGOOD
= 250µA 0.2 0.4 V
PGOOD Leakage V
PGOOD
= 2V 10 1000 nA
PGOOD Threshold (Relative to V
FB
) (Note 8) 86 90 94 %
Switching Regulator
Feedback Pin Voltage
l
735 750 765 mV
Feedback Pin Bias Current
l
–50 –500 nA
Error Amplifier Transconductance 350 µS
Error Amplifier Voltage Gain 600 V/V
TRK/SS Pull-Up Current –2 –3 –4 µA
TRK/SS Threshold to Start Switching 35 50 70 mV
V
C1
Source Current V
C
= 0.6V –20 µA
V
C1
Sink Current V
C
= 0.6V 28 µA
V
C1
Clamp Voltage 2 V
V
C1
Switching Threshold 0.75 V
V
C1
to Switch Current Gain 3.6 A/V
Switch Leakage Current V
IN
= 36V 0.01 10 µA
Minimum Boost Voltage Above Switch (Note 4) 1.8 2.5 V
Switch Current Limit (Note 3) (Note 3) 10% Duty Cycle
l
3.5 4.9 6 A
Switch V
CESAT
I
SW1
= 3A 600 mV
BST Operating Current I
SW1
= 3A 60 mA
V
F
, BST Diode I
BST
= 100mA 0.8 V
I
L
BST Diode V
BST
– V
BIAS
= 36V 1 µA
DA Current Limit
l
2.6 3.6 4.5 A
Minimum Switch Off-Time
l
140 ns
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C, V
IN
= 12V, V
BIAS
= 3V, unless otherwise noted. (Notes 2, 9)