AIC1550 AIC [Analog Intergrations Corporation], AIC1550 Datasheet - Page 9

• Manufacturer Part Number: AIC1550
• Description: Low-Noise Synchronous PWM Step-Down DC/DC Converter
• Manufacturer: AIC [Analog Intergrations Corporation]

PIN 1: VIN-
PIN 2: BP-
PIN 3: SHDN - Active-Low,
PIN 4: FB-
PIN 5: RT-
BLOCK DIAGRAM
PIN DESCRIPTIONS
S H D N
S YN C
FB
RT
B P
R E F
Frequency
S election
R E F
FB
Supply Voltage Input ranging from
+2.5V to +6.5V. Bypass with a
22µF capacitor.
Supply
connecting to VIN. Bypass with a
0.1µF capacitor.
Input reducing supply current to
0.1µA in shutdown mode.
Feedback Input.
Frequency
connecting to GND through a
resistor to increase frequency.
(Refer to Fig. 15)
O scillator
500K H z
0.75V
R E F
C om pensation
+
+
-
-
P hase
Bypass
E rror
C om pensation
A MP
C om parator
P FM
Adjustable
S lope
.
Shutdown-Control
Pin
C urrent A MP
P W M/P FM
internally
-
+
C ontrol
P W M
C om parator
Pin
.
X 5
+
-
C hip S upply
C ontrol Logic
C urrent Lim it
C om parator
PIN 6: SYNC/MODE-
PIN 7: GND-
PIN 8: LX-
Zero C ross
C om parator
+
10
-
V IN
R E F
T hrough
S hoot-
A nti-
Oscillator Sync and Low-Noise,
Mode-Control Input.
SYNC/MODE
PWM Mode)
SYNC/MODE = GND (PWM/PFM
Mode)
An
connecting to this pin allows LX
switching synchronization.
Ground.
Inductor connecting to the Drains
of the Internal Power MOSFETs
+
-
external
Q 1
x1
5
Q 2
X20
Q 3
=
AIC1550
clock
VIN
V IN
LX
G N D
(Forced
signal
9