LTC3830-1ES8 Linear Technology, LTC3830-1ES8 Datasheet - Page 6

• Manufacturer Part Number: LTC3830-1ES8
• Description: IC DC/DC CONTRLR STEP-DWN 8-SOIC
• Manufacturer: Linear Technology
• Type: Step-Down (Buck)r

Specifications of LTC3830-1ES8

• Internal Switch(s): No
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 3.3V, Adj
• Current - Output: 20A
• Frequency - Switching: 200kHz
• Voltage - Input: 3 ~ 8 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power - Output: -
• Other names: LTC38301ES8

PI FU CTIO S
LTC3830/LTC3830-1
G1 (Pin 1/Pin 1/Pin 1): Top Gate Driver Output. Connect
this pin to the gate of the upper N-channel MOSFET, Q1.
This output swings from PGND to PV
G2 is high or during shutdown mode.
PV
Connect this pin to a potential of at least V
This potential can be generated using an external supply or
charge pump.
PGND (Pin 3/Pin 3/Pin 3): Power Ground. Both drivers
return to this pin. Connect this pin to a low impedance
ground in close proximity to the source of Q2. Refer to the
Layout Consideration section for more details on PCB
layout techniques. The LTC3830-1 and the 8-lead LTC3830
have PGND and GND tied together internally at Pin 3.
GND (Pin 4/Pin 3/Pin 3): Signal Ground. All low power
internal circuitry returns to this pin. To minimize regula-
tion errors due to ground currents, connect GND to PGND
right at the LTC3830.
SENSE
three pins connect to the internal resistor divider and input
of the error amplifier. To use the internal divider to set the
output voltage to 3.3V, connect SENSE
terminal of the output capacitor and SENSE
tive terminal. FB should be left floating. To use an external
TYPICAL PERFOR A CE CHARACTERISTICS
6
CC1
U
50
40
10
30
20
0
PV
vs Gate Capacitance
0
T
(Pin 2/Pin 2/Pin 2): Power Supply Input for G1.
–
A
CC
, FB, SENSE
GATE CAPACITANCE AT G1 AND G2 (nF)
= 25°C
1
U
Supply Current
2
3
4
PV
U
PV
5
CC1,2
+
CC1,2
(Pins 5, 6, 7/Pin 4/Pin 4): These
6
= 12V
= 5V
7
(16-Lead LTC3830/8-Lead LTC3830/LTC3830-1)
W
8
3830 G20
9
U
10
CC1
. It remains low if
+
IN
to the positive
+ V
–
200
180
160
140
120
100
80
60
40
20
to the nega-
0
0
GS(ON)(Q1)
G1 Rise/Fall Time
vs Gate Capacitance
T
A
GATE CAPACITANCE AT G1 AND G2 (nF)
1
= 25°C
2
t
r
AT PV
t
f
AT PV
3
.
CC1,2
4
CC1,2
t
resistor divider to set the output voltage, float SENSE
SENSE
The internal resistor divider is not included in the LTC3830-1
and the 8-lead LTC3830.
SHDN (Pin 8/Pin 5/NA): Shutdown. A TTL compatible low
level at SHDN for longer than 100µs puts the LTC3830 into
shutdown mode. In shutdown, G1 and G2 go low, all
internal circuits are disabled and the quiescent current
drops to 10µA max. A TTL compatible high level at SHDN
allows the part to operate normally. This pin also doubles
as an external clock input to synchronize the internal
oscillator with an external clock. The shutdown function is
disabled in the LTC3830-1.
SS (Pin 9/NA/Pin 5): Soft-Start. Connect this pin to an
external capacitor, C
If the LTC3830 goes into current limit, C
to reduce the duty cycle. C
during power-up, the current through Q1 will not exceed
the current limit level. The soft-start function is disabled in
the 8-lead LTC3830.
COMP (Pin 10/Pin 6/Pin 6): External Compensation. This
pin internally connects to the output of the error amplifier
and input of the PWM comparator. Use a RC + C network
at this pin to compensate the feedback loop to provide
optimum transient response.
= 5V
r
5
AT PV
= 5V
t
f
6
AT PV
CC1,2
7
–
CC1,2
= 12V
and connect the external resistor divider to FB.
8
= 12V
3830 G21
9
10
50mV/DIV
SS
2AV/DIV
, to implement a soft-start function.
I
V
LOAD
OUT
SS
Transient Response
must be selected such that
50µs/DIV
SS
is discharged
3830 G22.tif
+
3830fa
and