Datasheet

2
LTC1627
T
JMAX
= 125°C, θ
JA
= 110°C/W
ORDER PART
NUMBER
S8 PART MARKING
TOP VIEW
SYNC/FCB
V
DR
V
IN
SW
I
TH
RUN/SS
V
FB
GND
S8 PACKAGE
8-LEAD PLASTIC SO
1
2
3
4
8
7
6
5
Consult factory for Military grade parts.
(Note 1)
Input Supply Voltage ................................ –0.3V to 10V
Driver Supply Voltage (V
IN
– V
DR
) ........... –0.3V to 10V
I
TH
Voltage .................................................. –0.3V to 5V
Run/SS, V
FB
Voltages ................................ –0.3V to V
IN
Sync/FCB Voltage ...................................... –0.3V to V
IN
V
DR
Voltage (V
IN
≤ 5V) ............................... –5V to 0.3V
P-Channel Switch Source Current (DC) .............. 800mA
N-Channel Switch Sink Current (DC) .................. 800mA
Peak SW Sink and Source Current ......................... 1.5A
Operating Ambient Temperature Range
Commercial ............................................ 0°C to 70°C
Industrial ........................................... –40°C to 85°C
Junction Temperature (Note 2).............................125°C
Storage Temperature Range ................. –65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
1627
1627I
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
VFB
Feedback Current (Note 3) 20 60 nA
V
FB
Regulated Feedback Voltage (Note 3) ● 0.788 0.80 0.812 V
∆V
OVL
∆Output Overvoltage Lockout ∆V
OVL
= V
OVL
– V
FB
20 60 110 mV
∆V
FB
Reference Voltage Line Regulation V
IN
= 2.8V to 8.5V (Note 3) 0.002 0.01 %/V
V
LOADREG
Output Voltage Load Regulation I
TH
Sinking 2µA (Note 3) 0.5 0.8 %
I
TH
Sourcing 2µA (Note 3) –0.5 –0.8 %
I
S
Input DC Bias Current (Note 4)
Synchronized V
IN
= 8.5V, V
OUT
= 3.3V, Frequency = 525kHz 450 µA
Burst Mode Operation V
ITH
= 0V, V
IN
= 8.5V, V
SYNC/FCB
= Open 200 320 µA
Shutdown V
RUN/SS
= 0V, 2.65V < V
IN
< 8.5V 15 35 µA
Shutdown V
RUN/SS
= 0V, V
IN
< 2.65V 6 µA
V
RUN/SS
Run/SS Threshold 0.4 0.7 1.0 V
I
RUN/SS
Soft-Start Current Source V
RUN/SS
= 0V 1.2 2.25 3.3 µA
V
SYNC/FCB
Auxiliary Feedback Threshold V
SYNC/FCB
Ramping Negative 0.730 0.8 0.860 V
I
SYNC/FCB
Auxiliary Feedback Current V
SYNC/FCB
= 0V 0.5 1.5 2.5 µA
f
OSC
Oscillator Frequency V
FB
= 0.8V 315 350 385 kHz
V
FB
= 0V 35 kHz
V
UVLO
Undervoltage Lockout V
IN
Ramping Down from 3V (–40°C to 85°C) 2.3 2.50 2.65 V
V
IN
Ramping Up from 0V (–40°C to 85°C) 2.65 2.85 V
V
IN
Ramping Down from 3V (0°C to 70°C) 2.4 2.50 2.65 V
V
IN
Ramping Up from 0V (0°C to 70°C) 2.65 2.80 V
R
PFET
R
DS(ON)
of P-Channel FET (V
IN
– V
DR
) = 5V, I
SW
= 100mA 0.5 0.7 Ω
R
NFET
R
DS(ON)
of N-Channel FET I
SW
= –100mA 0.6 0.8 Ω
I
LSW
SW Leakage V
RUN/SS
= 0V ±10 ±1000 nA
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:
T
J
= T
A
+ (P
D
• 110°C/W)
Note 3: The LTC1627 is tested in a feedback loop that servos V
FB
to the
balance point for the error amplifier (V
ITH
= 0.8V).
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
LTC1627CS8
LTC1627IS8
The ● denotes specifications which apply over the full operating temperature
range, otherwise specifications are at T
A
= 25°C. V
IN
= 5V unless otherwise specified.
ELECTRICAL CHARACTERISTICS
ABSOLUTE AXI U RATI GS
WWWU
PACKAGE/ORDER I FOR ATIO
UU
W