LTC1625
ELECTRICAL CHARACTERISTICS
SYMBOL
BG t
R
BG t
F
V
INTVCC
V
LDOINT
V
LDOEXT
V
EXTVCC
Oscillator
f
OSC
f
H
/f
OSC
V
SYNC
R
SYNC
Oscillator Freqency
Maximum Synchronized Frequency Ratio
SYNC Pin Threshold (Figure 4)
SYNC Pin Input Resistance
PARAMETER
BG Transition Time
Rise Time
Fall Time
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Voltage Drop
EXTV
CC
Switchover Voltage
T
A
= 25°C, V
IN
= 15V unless otherwise noted.
MIN
TYP
50
50
q
CONDITIONS
C
LOAD
= 3300pF
C
LOAD
= 3300pF
6V < V
IN
< 30V, V
EXTVCC
= 4V
I
CC
= 20mA, V
EXTVCC
= 4V
I
CC
= 20mA, V
EXTVCC
= 5V
I
CC
= 20mA, V
EXTVCC
Ramping Positive
q
MAX
150
150
5.4
–2
300
UNITS
ns
ns
V
%
mV
V
Internal V
CC
Regulator
5.0
5.2
–1
180
4.5
135
Ramping Positive
4.7
150
1.5
0.9
50
1.2
V
kΩ
165
kHz
The
q
denotes specifications which apply over the full operating
temperature range.
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
according to the following formula:
LTC1625CGN/LTC1625IGN: T
J
= T
A
+ (P
D
• 130°C/W)
LTC1625CS/LTC1625IS: T
J
= T
A
+ (P
D
• 110°C/W)
Note 3:
The LTC1625 is tested in a feedback loop that adjusts V
OSENSE
to
achieve a specified error amplifier output voltage (I
TH
).
Note 4:
Typical in application circuit with EXTV
CC
tied to V
OUT
= 5V,
I
OUT
= 0A and FCB = INTV
CC
. Dynamic supply current is higher due
to the gate charge being delivered at the switching frequency. See
Applications Information.
Note 5:
Minimum input supply voltage is 3.9V at – 40°C for industrial
grade parts.
3
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