4
LTC1629/LTC1629-PG
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/SS1, 2
= 5V unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Note 4: Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency. See Applications Information.
Note 5: When the AMPMD pin is high, the IC pins are connected directly to
the internal op amp inputs. When the AMPMD pin is low, internal MOSFET
switches connect four 40k resistors around the op amp to create a
standard unity-gain differential amp.
Note 6: The minimum on-time condition corresponds to the on inductor
peak-to-peak ripple current ≥40% of I
MAX
(see Minimum On-Time
Considerations in the Applications Information section).
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 formulas:
LTC1629/LTC1629-PG: T
J
= T
A
+ (P
D
• 95°C/W)
Note 3: The LTC1629/LTC1629-PG are tested in a feedback loop that
servos V
ITH
to a specified voltage and measures the resultant V
EAIN
.
V
OS
Input Offset Voltage Op Amp Mode; V
CM
= 2.5V; LTC1629 Only 6 mV
V
DIFFOUT
= 5V; I
DIFFOUT
= 1mA
I
B
Input Bias Current Op Amp Mode; LTC1629 Only 30 200 nA
A
OL
Open Loop DC Gain Op Amp Mode; 0.7V ≤ V
DIFFOUT
< 10V; LTC1629 Only 5000 V/mV
V
CM
Common Mode Input Voltage Range Op Amp Mode; LTC1629 Only 0 3 V
CMRR
OA
Common Mode Rejection Ratio Op Amp Mode; 0V < V
CM
< 3V; LTC1629 Only 70 90 dB
PSRR
OA
Power Supply Rejection Ratio Op Amp Mode; 6V < V
IN
< 30V; LTC1629 Only 70 90 dB
I
CL
Maximum Output Current Op Amp Mode; V
DIFFOUT
= 0V; LTC1629 Only 10 35 mA
V
OMAX
Maximum Output Voltage Op Amp Mode; I
DIFFOUT
= 1mA; LTC1629 Only 10 11 V
GBW Gain-Bandwidth Product Op Amp Mode; I
DIFFOUT
= 1mA; LTC1629 Only 2 MHz
SR Slew Rate Op Amp Mode; R
L
= 2k; LTC1629 Only 5 V/µs
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Efficiency vs Output Current
(Figure 12)
Efficiency vs Output Current
(Figure 12)
Efficiency vs Input Voltage
(Figure 12)
OUTPUT CURRENT (A)
0.1
EFFICIENCY (%)
100
80
60
40
20
0
1629 G01
1 10 100
V
OUT
= 3.3V
V
EXTVCC
= 5V
I
OUT
= 20A
V
IN
= 5V
V
IN
= 8V
V
IN
= 12V
V
IN
= 20V
OUTPUT CURRENT (A)
1
EFFICIENCY (%)
70
80
1629 G02
60
50
10 100
100
90
V
EXTVCC
= 0V
V
OUT
= 3.3V
V
EXTVCC
= 5V
V
IN
(V)
5
EFFICIENCY (%)
100
90
80
70
1629 G03
10 15 20
V
OUT
= 3.3V
V
EXTVCC
= 5V
I
OUT
= 20A
