4
LTC1709-8/LTC1709-9
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 15V, V
RUN/SS
= 5V unless otherwise noted.
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 corresponds to the on inductor
peak-to-peak ripple current ≥40% I
MAX
(see Minimum On-Time
Considerations in the Applications Information section).
Note 8: Each built-in pull-up resistor attached to the VID inputs also has a
series diode to allow input voltages higher than the VIDV
CC
supply without
damage or clamping (see the Applications Information section).
Note 1: Absolute Maximum Ratings are those values beyond which the
life of a device may be impaired.
Note 2: The LTC1709EG is guaranteed to meet performance specifications
from 0°C to 70°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
LTC1709EG: T
J
= T
A
+ (P
D
• 85°C/W)
Note 4: The LTC1709-8/LTC1709-9 are tested in a feedback loop that
servos V
ITH
to a specified voltage and measures the resultant V
EAIN
.
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Efficiency vs Output Current
(Figure 12)
OUTPUT CURRENT (A)
0.1
EFFICIENCY (%)
100
80
60
40
20
0
170989 G01
1 10 100
V
OUT
= 2V
V
EXTVCC
= 0V
FREQ = 200kHz
V
IN
= 5V
V
IN
= 8V
V
IN
= 12V
V
IN
= 20V
Efficiency vs Output Current
(Figure 12)
V
IN
(V)
5
EFFICIENCY (%)
100
90
80
70
170989 G03
10 15 20
V
OUT
= 3.3V
V
EXTVCC
= 5V
I
OUT
= 20A
Efficiency vs Output Current
(Figure 12)
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
PGOOD Output
V
PGL
PGOOD Voltage Low I
PGOOD
= 2mA 0.1 0.3 V
I
PGOOD
PGOOD Leakage Current V
PGOOD
= 5V ±1 µA
V
PG
PGOOD Trip Level, Either Controller V
EAIN
with Respect to Set Output Voltage
V
EAIN
Ramping Negative –6 –7.5 –9.5 %
V
EAIN
Ramping Positive 6 7.5 9.5 %
Differential Amplifier/Op Amp Gain Block
A
DA
Gain 0.995 1 1.005 V/V
CMRR
DA
Common Mode Rejection Ratio 0V < V
CM
< 5V 46 55 dB
R
IN
Input Resistance Measured at V
OS
+ Input 80 kΩ
OUTPUT CURRENT (A)
0.1
EFFICIENCY (%)
40
60
170989 G02
20
0
101 100
100
80
V
IN
= 12V
V
OUT
= 2V
FREQ = 200kHz
V
EXTVCC
= 5V
V
EXTVCC
= 0V
