LTM4636
5
4636f
elecTrical characTerisTics
The
l
denotes the specifications which apply over the specified internal
operating temperature range (Note 2), otherwise specifications are at T
A
= 25°C. V
IN
= 12V, per the typical application in Figure 20.
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 LTM4636 is tested under pulsed load conditions such that
T
J
≈ T
A
. The LTM4636E is guaranteed to meet performance specifications
over the 0°C to 125°C internal operating temperature range. Specifications
over the full –40°C to 125°C internal operating temperature range are
assured by design, characterization and correlation with statistical process
controls. The LTM4636I is guaranteed to meet specifications over the
full –40°C to 125°C internal operating temperature range. 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 resistance and other environmental
factors.
Note 3:
The minimum on-time condition is specified for a peak-to-peak
inductor ripple current of ~40% of I
MAX
Load. (See the Applications
Information section)
Note 4:
See output current derating curves for different V
IN
, V
OUT
and T
A
.
Note 5:
Guaranteed by design.
Note 6:
100% tested at wafer level.
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Temperature Diode
Diode V
F
Diode Forward Voltage
I = 100µA, TEMP
+
to TEMP
–
0.598
V
TC
Temperature Coefficient
l
–2.0
mV/°C
Typical perForMance characTerisTics
Burst Mode Efficiency
vs Load Current
1V Transient Response
1.2V Transient Response
Efficiency vs Load Current
with 5V
IN
Efficiency vs Load Current with
8V
IN
Efficiency vs Load Current with
12V
IN
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
100
90
80
95
85
75
70
25
15
35
4636 G01
40
20
10
5
30
3.3V
OUT
, 500kHz
2.5V
OUT
, 500kHz
1.8V
OUT
, 450kHz
1.5V
OUT
, 425kHz
1.2V
OUT
, 300kHz
1V
OUT
, 300kHz
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
100
90
80
95
85
75
70
25
15
35
4636 G02
40
20
10
5
30
3.3V
OUT
, 700kHz
2.5V
OUT
, 600kHz
1.8V
OUT
, 500kHz
1.5V
OUT
, 450kHz
1.2V
OUT
, 400kHz
1V
OUT
, 350kHz
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
100
90
80
95
85
75
70
25
15
35
4636 G03
40
20
10
5
30
3.3V
OUT
, 750kHz
2.5V
OUT
, 650kHz
1.8V
OUT
, 600kHz
1.5V
OUT
, 550kHz
1.2V
OUT
, 400kHz
1V
OUT
, 350kHz
OUTPUT CURRENT (A)
0
EFFICIENCY (%)
100
80
60
90
70
50
40
3
2
4
4636 G04
5
1
Burst Mode OPERATION
V
IN
12V
V
OUT
1.5V
12V TO 1V TRANSIENT RESPONSE
C
OUT
= 4 × 100µF CERAMIC, 3 × 470µF 2.5V
POSCAP 5mΩ
C
FF
= 22pF, SW FREQ = 400kHz
10A/DIV
18A/µs
STEP
50mV/DIV
50µs/DIV
4636 G05
12V TO 1.2V TRANSIENT RESPONSE
C
OUT
= 4 × 100µF CERAMIC, 3 × 470µF 2.5V
POSCAP 5mΩ
C
FF
= 22pF, SW FREQ = 400kHz
C
COMP
= 100pF
10A/DIV
18A/µs
STEP
50mV/DIV
50µs/DIV
4636 G06
