4
LTC1709-7
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
BIAS
= 5V, 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-7 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-7: T
J
= T
A
+ (P
D
• 85°C/W)
Note 4: The LTC1709-7 is 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 Load Current
(3 Operating Modes) (Figure 12)
LOAD CURRENT (A)
0
EFFICIENCY (%)
10
30
40
50
100
70
0.01
0.1
1
17097 G01
20
80
90
60
10010
FORCED
CONTINUOUS
MODE
Burst Mode
OPERATION
V
IN
= 5V
V
OUT
= 1.6V
FREQ = 200kHz
CONSTANT
FREQUENCY
(BURST DISABLE)
Efficiency vs Output Current
(Figure 12)
OUTPUT CURRENT (A)
0.1
EFFICIENCY (%)
100
80
60
40
20
0
17097 G02
1 10 100
V
OUT
= 2V
V
EXTVCC
= 0V
FREQ = 200kHz
V
FCB
= 0V
V
IN
= 5V
V
IN
= 8V
V
IN
= 12V
V
IN
= 20V
INPUT VOLTAGE (V)
5
EFFICIENCY (%)
70
80
17097 G03
60
50
10
V
OUT
= 1.6V
15
20
100
90
V
OUT
= 2V
I
OUT
= 20A
Efficiency vs Input Voltage
(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
