LTC3850EUF#PBF Linear Technology, LTC3850EUF#PBF Datasheet - Page 5

• Manufacturer Part Number: LTC3850EUF#PBF
• Description: IC CNTRLR STP DWN SYNC 28-QFN
• Manufacturer: Linear Technology
• Series: PolyPhase®r
• Type: Step-Down (Buck)r

Specifications of LTC3850EUF#PBF

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 0.8 ~ 23.3 V
• Current - Output: 100mA
• Frequency - Switching: 250kHz ~ 780kHz
• Voltage - Input: 4 ~ 24 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-QFN
• Primary Input Voltage: 24V
• No. Of Outputs: 2
• Output Current: 100mA
• No. Of Pins: 28
• Operating Temperature Range: -40°C To +85°C
• Msl: MSL 1 - Unlimited
• Supply Voltage Range: 4V To 24V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -

ELECTRICAL CHARACTERISTICS
SYMBOL
Oscillator and Phase-Locked Loop
f
f
f
R
I
PGOOD Output
V
I
V
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 LTC3850E/LTC3850E-1 are guaranteed to meet performance
specifications from 0°C to 85°C. Specifications over the –40°C to 85°C
operating temperature range are assured by design, characterization and
correlation with statistical process controls. The LTC3850I/LTC3850I-1 are
guaranteed to meet performance specifications over the –40°C to 85°C
operating temperature range.
Note 3: T
dissipation P
TYPICAL PERFORMANCE CHARACTERISTICS
temperature range, otherwise specifications are at T
NOM
LOW
HIGH
FREQ
PGOOD
PGL
PG
MODE/PLLIN
100
90
80
70
60
40
30
20
10
50
0
10
Efficiency vs Output Current
and Mode
CIRCUIT OF FIGURE 14
V
V
CCM
J
IN
OUT
is calculated from the ambient temperature T
= 12V
D
= 1.8V
according to the following formulas:
DCM
PARAMETER
Nominal Frequency
Lowest Frequency
Highest Frequency
MODE/PLLIN Input Resistance
Phase Detector Output Current
PGOOD Voltage Low
PGOOD Leakage Current
PGOOD Trip Level
Sinking Capability
Sourcing Capability
LOAD CURRENT (mA)
100
1000
BURST
10000
38501 G01
100
90
80
70
60
50
40
30
20
10
0
A
10
CIRCUIT OF FIGURE 14
and power
CONDITIONS
V
V
V
f
f
I
V
V
Efficiency vs Output Current
and Mode
MODE
MODE
PGOOD
FREQ
FREQ
FREQ
PGOOD
FB
V
V
A
with Respect to Set Regulated Voltage
FB
FB
DCM
= 25°C, V
CCM
= 1.2V
= 0V
≥ 2.4V
< f
> f
Ramping Negative
Ramping Positive
BURST
= 2mA
= 5V
OSC
OSC
The
LOAD CURRENT (mA)
100
l
IN
denotes the specifications which apply over the full operating
= 15V, V
Note 4: The LTC3850 is tested in a feedback loop that servos V
specified voltage and measures the resultant V
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
Considerations in the Applications Information section).
Note 8: V
1000
LTC3850GN: T
LTC3850UF: T
LTC3850UFD: T
RUN1,2
V
V
IN
OUT
= 12V
SENSE(MAX)
= 3.3V
= 5V, unless otherwise noted.
38501 G02
10000
J
J
= T
J
= T
= T
defaults to 50mV typical for the LTC3850-1.
LTC3850/LTC3850-1
A
A
100
A
+ (P
+ (P
95
90
85
80
+ (P
Efficiency and Power Loss
vs Input Voltage
5
CIRCUIT OF FIGURE 14
D
D
V
I
OUT
D
• 37°C/W)
OUT
• 95°C/W)
• 43°C/W)
= 2A
= 3.3V
MIN
10
450
210
700
–5
MAX
5
INPUT VOLTAGE (V)
EFFICIENCY
POWER LOSS
(see Minimum On-Time
15
FB1,2
– 7.5
TYP
500
250
780
250
–13
0.1
7.5
13
.
20
MAX
550
290
860
–10
0.3
±2
10
ITH1,2
38501 G03
25
2000
1500
1000
500
0
UNITS
38501fc
to a
5
kHz
kHz
kHz
kΩ
µA
µA
µA
%
%
V