Storage Temperature Range .................. –65°C to 150°C
I
LIM
20 19 18 17
PLLIN/MODE 1
SGND 2
SGND 3
RUN 4
SENSE
–
V
IN
16 PGND
15 EXTV
CC
14 INTV
CC
13 BG
12 BOOST
11 SW
TG
21
SGND
5
SENSE
+
6
7
V
FB
8
ITH
9 10
PGOOD
UDC PACKAGE
20-LEAD (3mm
×
4mm) PLASTIC QFN
T
JMAX
= 150°C,
θ
JA
= 52°C/W
EXPOSED PAD (PIN 21) IS SGND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC7800EUDC#PBF
LTC7800IUDC#PBF
LTC7800HUDC#PBF
TAPE AND REEL
LTC7800EUDC#TRPBF
LTC7800IUDC#TRPBF
LTC7800HUDC#TRPBF
http://www.linear.com/product/LTC7800#orderinfo
PART MARKING*
LHBS
LHBS
LHBS
PACKAGE DESCRIPTION
20-Lead (3mm × 4mm) Plastic QFN
20-Lead (3mm × 4mm) Plastic QFN
20-Lead (3mm × 4mm) Plastic QFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 150°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to:
http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to:
http://www.linear.com/tapeandreel/.
Some packages are available in 500 unit reels through
designated sales channels with #TRMPBF suffix.
7800f
2
For more information
www.linear.com/LTC7800
LTC7800
ELECTRICAL CHARACTERISTICS
SYMBOL
V
IN
V
FB
PARAMETER
Input Supply Operating Voltage Range
Regulated Feedback Voltage
(Note 4); I
TH
Voltage = 1.2V
–40°C to 85°C
LTC7800E, LTC7800I
LTC7800H
(Note 4)
(Note 4); V
IN
= 4.5V to 60V
(Note 4)
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 0.7V
(Note 4)
Measured in Servo Loop;
∆I
TH
Voltage = 1.2V to 2V
g
m
I
Q
Transconductance Amplifier g
m
Input DC Supply Current
Pulse Skip or Forced Continuous Mode
Sleep Mode
Shutdown
UVLO
V
OVL
I
SENSE+
I
SENSE–
DF
MAX
I
TRACK/SS
V
RUN
On
V
RUN
Hyst
V
SENSE(MAX)
Gate Driver
TG
BG
TG t
r
TG t
f
BG t
r
BG t
f
TG/BG t
1D
BG/TG t
1D
Pull-Up On-Resistance
Pull-Down On-Resistance
Pull-Up On-Resistance
Pull-Down On-Resistance
TG Transition Time:
Rise Time
Fall Time
BG Transition Time:
Rise Time
Fall Time
Top Gate Off to Bottom Gate On Delay
Synchronous Switch-On Delay Time
Bottom Gate Off to Top Gate On Delay
Top Switch-On Delay Time
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
(Note 6)
C
LOAD
= 3300pF
C
LOAD
= 3300pF
C
LOAD
= 3300pF
C
LOAD
= 3300pF
2.5
1.5
2.4
1.1
25
16
25
13
20
20
Ω
Ω
Ω
Ω
ns
ns
ns
ns
ns
ns
7800f
The
l
denotes the specifications which apply over the specified
operating junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V, V
RUN
= 5V, EXTV
CC
= 0V unless
otherwise noted.
CONDITIONS
MIN
4
0.792
0.788
0.786
0.800
0.800
0.800
±5
0.002
l
TYP
MAX
60
0.808
0.812
0.812
±50
0.02
0.1
UNITS
V
V
V
V
nA
%/V
%
l
l
I
FB
V
REFLNREG
V
LOADREG
Feedback Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
0.01
l
–0.01
–0.1
%
(Note 4); I
TH
= 1.2V; Sink/Source 5µA
(Note 5)
V
FB
= 0.83V (No Load)
V
FB
= 0.83V (No Load)
RUN = 0V
INTV
CC
Ramping Up
INTV
CC
Ramping Down
Measured at V
FB
Relative to Regulated V
FB
V
SENSE–
< INTV
CC
– 0.5V
V
SENSE–
> INTV
CC
+ 0.5V
In Dropout; V
FREQ
= 0V
V
TRACK/SS
= 0V
V
RUN
Rising
V
FB
= 0.7V, V
SENSE–
= 3.3V, I
LIM
= 0V
V
FB
= 0.7V, V
SENSE–
= 3.3V, I
LIM
= INTV
CC
V
FB
= 0.7V, V
SENSE–
= 3.3V, I
LIM
= FLOAT
l
l
l
2
2
50
14
3.6
7
3.92
3.80
10
75
25
4.2
4.0
13
±1
700
97
7
1.15
22
43
64
98
10
1.21
50
l
l
l
mmho
mA
µA
µA
V
V
%
µA
µA
µA
%
14
1.27
36
57
85
µA
V
mV
mV
mV
mV
Undervoltage Lockout
Feedback Overvoltage Protection
SENSE
+
Pin Current
SENSE
–
Pins Current
Maximum Duty Factor
Soft-Start Charge Current
RUN Pin On Threshold
RUN Pin Hysteresis
Maximum Current Sense Threshold
±2
30
50
75
For more information
www.linear.com/LTC7800
3
LTC7800
ELECTRICAL CHARACTERISTICS
SYMBOL
t
ON(MIN)
V
INTVCCVIN
V
LDOVIN
V
INTVCCEXT
V
LDOEXT
V
EXTVCC
V
LDOHYS
f
25kΩ
f
65kΩ
f
100kΩ
f
LOW
f
HIGH
f
SYNC
PLLIN V
IH
PLLIN V
IL
PGOOD1 Output
V
PGL
I
PGOOD
V
PG
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
I
PGOOD
= 2mA
V
PGOOD
= 5V
V
FB
with Respect to Set Regulated Voltage
V
FB
Ramping Negative
Hysteresis
V
FB
Ramping Positive
Hysteresis
t
PG
Delay for Reporting a Fault
7
–13
–10
2.5
10
2.5
25
13
–7
%
%
%
%
µs
0.2
0.4
±1
V
µA
PARAMETER
Minimum TG On-Time
Internal V
CC
Voltage
INTV
CC
Load Regulation
Internal V
CC
Voltage
INTV
CC
Load Regulation
EXTV
CC
Switchover Voltage
EXTV
CC
Hysteresis
Programmable Frequency
Programmable Frequency
Programmable Frequency
Low Fixed Frequency
High Fixed Frequency
Synchronizable Frequency
PLLIN/MODE Input High Level
PLLIN/MODE Input Low Level
R
FREQ
= 25k;
PLLIN/MODE = DC Voltage
R
FREQ
= 65k;
PLLIN/MODE = DC Voltage
R
FREQ
=100k;
PLLIN/MODE = DC Voltage
V
FREQ
= 0V;
PLLIN/MODE = DC Voltage
V
FREQ
= INTV
CC
;
PLLIN/MODE = DC Voltage
PLLIN/MODE = External Clock
PLLIN/MODE = External Clock
PLLIN/MODE = External Clock
l
l
l
l
The
l
denotes the specifications which apply over the specified
operating junction temperature range, otherwise specifications are at T
A
= 25°C (Note 2), V
IN
= 12V, V
RUN
= 5V, EXTV
CC
= 0V unless
otherwise noted.
CONDITIONS
(Note 7)
6V < V
IN
< 60V, V
EXTVCC
= 0V
I
CC
= 0mA to 50mA, V
EXTVCC
= 0V
6V < V
EXTVCC
< 13V
I
CC
= 0mA to 50mA,
V
EXTVCC
= 8.5V
I
CC
= 0mA to 50mA,
EXTV
CC
Ramping Positive
4.5
4.85
4.85
MIN
TYP
45
5.1
0.7
5.1
0.6
4.7
250
0.27
0.32
1.18
1.75
0.79
1.2
0.32
2.5
0.5
2.1
0.94
1.44
2.4
1.08
1.7
2.25
0.36
5.35
1.1
5.35
1.1
4.9
MAX
UNITS
ns
V
%
V
%
V
mV
MHz
MHz
MHz
MHz
MHz
MHz
V
V
INTV
CC
Linear Regulator
Oscillator and Phase-Locked Loop
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 LTC7800 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTC7800E is guaranteed to meet performance specifications
from 0°C to 85°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 LTC7800I is guaranteed
over the –40°C to 125°C operating junction temperature range, the
LTC7800H is guaranteed over the –40°C to 150°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes; operating lifetime is derated for junction temperatures greater
than 125°C. 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.
Note 3:
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
is 52°C/W.
7800f
4
For more information
www.linear.com/LTC7800
LTC7800
ELECTRICAL CHARACTERISTICS
Note 4:
The LTC7800 is tested in a feedback loop that servos V
ITH
to a
specified voltage and measures the resultant V
FB
. The specification at 85°C
is not tested in production and is assured by design, characterization and
correlation to production testing at other temperatures (125°C for the
LTC7800E/LTC7800I and 150°C for the LTC7800H.)
Note 5:
Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 6:
Rise and fall times are measured using 10% and 90% levels. Delay
times are measured using 50% levels
Note 7:
The minimum on-time condition is specified for an inductor
peak-to-peak ripple current ≥ 40% of I
MAX
(See Minimum On-Time
Considerations in the Applications Information section).
Note 8:
Do not apply a voltage or current source to these pins. They must
be connected to capacitive loads only, otherwise permanent damage may
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