at1780 Aimtron Technology, at1780 Datasheet - Page 4

• Manufacturer Part Number: at1780
• Description: 640khz/1.2mhz,low-noise Step-up Current-mode Pwm Controller
• Manufacturer: Aimtron Technology

Entire device
Error amplifier
Sawtooth wave
oscillator (OSC)
N-CHANNEL
SWITCH
SOFT-START
CONTROL INPUTS
Electrical Characteristics
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] Fax: [phone]
3/24/06 REV 1.1
(VIN = SHDN = 3V, FREQ = GND, TA =0℃ to +85℃, unless otherwise noted. Typical values are at TA = +25℃.)
Parameter
Input Supply Range
VIN
Lockout
Quiescent Current
Shutdown Supply
Current
Feedback Voltage
FB Input Bias Current
Feedback-Voltage Line
Regulation
Transconductance
Voltage Gain
Frequency
Maximum Duty Cycle
Current Limit
On-Resistance
Leakage Current
Current-Sense
Transresistance
Reset Switch
Resistance
Charge Current
Input Low Voltage
Input High Voltage
Hysteresis
FSLC Pull-Down
Current
/SHDN Input Current
Undervoltage
Symbol
UVLO
I
I
I
LXOFF
fosc
R
V
V
I
DC
R
V
SHDN
gm
V
Av
FSLC
I
I
I
LIM
FB
IN
IN
ON
IN
CS
FB
IL
IH
4
640kHz/1.2MHz,Low-Noise Step-Up
V
hysteresis is 40mV,LX
remains off below this
level
V
switching
/SHDN = GND
Level to produce
V
VFB = 1.25V
Level to produce
V
2.6V < V
ΔI = 5µA
FSLC = GND
FSLC = IN
FSLC = GND
FSLC = IN
V
65%
I
V
V
/SHDN, FREQ;
V
/SHDN, FREQ;
V
SHDN, FREQ
Preliminary Product Information
V
LX
IN
FB
COMP
COMP
FB
LX
SS
IN
IN
FB
= 1.2A
rising, typical
= 2.6V to 5.5V
= 2.6V to 5.5V
= 1.2V
Current-Mode PWM Controller
= 1.3V, not
= 1V, duty cycle =
= 12V
= 1.0V, switching
Condition
= 1.24V,
= 1.24V
WWW:
IN
Email:
--
< 5.5V
http://www.aimtron.com.tw
[e-mail]
1.222 1.24 1.258
Min. Typ. Max.
1050 1200 1350
540
100
2.6
2.1
1.2
0.3
1.5
1.6
1.5
79
Values
AT1780
0.218 0.35
2.045
0.001
0.05 0.15 %/V
91.3
82.1
0.21
0.01
0.45 0.65 V/A
140
500
640
2.3
0.1
1.6
0
4
5
740
100
5.5
2.5
2.3
0.5
0.4
10
40
92
20
5
7
9
1
μmhos
Unit
μA
V/V
μA
μA
μA
μA
kHz
mA
mV
nA
Ω
Ω
%
V
V
V
A
V
V