AS1720
26个字母书写笔顺Solenoid / Valve Driver with Current Limitation
Datasheet
1 General Description
The AS1720A is a low side current source providing an optimized DC Operation for power saving and ultra low electromagnetic radiation.
The AS1720B is a low side switch providing a PWM output, which frequency is defined by an internal RC oscillator. The adjustable PWM allows a fine control of the power delivered to the load. The AS1720A and AS1720B can be t to provide a strong initial closure current and is automatically switching to hold mode for power saving. The initial DC current, the hold current and the duty cycle of the PWM can be adjusted by external resistors. An internal thermal nsor prevents damage of the circuit due to excessive heating up.
Both devices are optimized for driving electromechanical devices such as valves, solenoids relays, actuators and positioners.
2 Key Features
Supply Range: +5V to +50V Internal VDDA: 3.3V Supply Current: 1 mA Internal osc frequency: 30kHz Fix delay: 136ms
Adjustable duty cycle: 20% – 90% (AS1720B only)
Adjustable energizing current: 10mA – 100mA Adjustable hold current: 30% - 70% of energizing current Current Limitation Thermal shutdown: 150ºC 8-pin MLPD (2x2mm) Package
On request SOIC 8 Package (reduced temperature range -40°C
to +85°C)
3 Applications
The AS1720 is ideal for fluid and gas flow systems, industrial control, electrical heaters, motor speed control.
Table 1. Standard Products
Model Operation Mode AS1720A DC Current Source Operation AS1720B
PWM Switching Operation
L
Energising Current adjust
Thermal Shutdown PWM &Control
Free-Wheeling Diode
Vsupply: +5V to +50V
IH
ENN
IE
adjustable Duty cycle
Hold Current adjust
Internal VDDA typ. 3.3V
Current Adjust
LDO &Ref Generator
R1
R2
V ref
100nF
R PU
On
Off AS1720
暴走大事件第三季
Delay
30kHz Oscillator
VDDA 3DUTY
2VDDA
1
VDDHV
4OUT
5VSS
7
6
8
Figure 1. AS1720 - Block Diagram
R IE
小清新唯美图片R IH
R L
10nF
4 Pin Assignments
Figure 2. Pin Out (Top View)
Pin Description
Table 2. Pin Descriptions
Pin Name Pin Number Description VDDHV1Positive supply voltage
VDDA2Internal supply of 3.3V (typ.)
DUTY3Duty-Cycle. By means of this pin the duty cycle can be adjusted between 20% and 90% during hold pha. The duty cycle can be adjusted by a voltage source or an external resistor divider. Setting this pin to V DDA the 50% duty cycle is lected automatically.
OUT4Current Source Output
VSS5Ground
IE6Energize Current. This pin defines the current during energize pha by means of a resistor. IH7Hold Current. This pin defines the current during hold pha by means of a resistor.
ENN8Enable Not. This pin can be ud to switch on/off the current source (e.g. via a µP), when the
AS1720 is always powered on.
Low during start-up: When VDDHV is applied, the device starts with the energi pha, followed by the hold pha.
When the device is constantly powered on, it can be controlled by this pin.一千克是几斤
High: The output current source is switched off.
Low: The device starts with the energi pha, followed by the hold pha.
5 Absolute Maximum Ratings
Stress beyond tho listed in Table 3 may cau permanent damage to the device. The are stress ratings only, and functional operation of the device at the or any other conditions beyond tho indicated in Section 6 Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Table 3. Absolute Maximum Ratings
Parameter Min Max Units Notes
Electrical Parameters
VDDHV, OUT-0.9+55V
VDDA, DUTY, ENN, IE, IH-0.3+5V
Input Current (latch-up immunity) -100100mA Norm: JEDEC 78 @85°C Electrostatic Discharge
Electrostatic Discharge HBM+/- 1.5kV Norm: MIL 883 E method 3015 Temperature Ranges and Storage Conditions
Thermal Resistance θJA+36ºC/W
Junction Temperature T J+140ºC Internally limited
Storage Temperature Range-55+150ºC
Package Body Temperature +260ºC
The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State
Surface Mount Devices”.
The lead finish for Pb-free leaded packages is
matte tin (100% Sn).
Humidity585%Non-condensing
Moisture Sensitive Level1Reprents a max. floor life time of unlimited
6 Electrical Characteristics
V DDHV = 5V, V SS = 0V, Typical Values are at T AMB = +25ºC (unless otherwi specified). All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods.
媚者无疆长安Table 4. Electrical Characteristics
Symbol Parameter Conditions Min Typ Max Units T AMB Operating Ambient Temperature-40+85°C T J Operating Junction Temperature-40+125°C valid for AS1720A & AS1720B
V DDHV Supply Voltage Range550V V DDA Internal Supply no load 3.1 3.3 3.5V
I DD Supply Current12mA
I OUT_E Output Energizing Current Range1
在思想上1.The parameters are tested with proprietary test modes.
defined by R IE
(e Figure 10 on page 7)
10100mA
V IH
Digital Input Threshold@ pin ENN 2V DDA
V
V IL V SS 1.2
V HYST Hysteresis@ pin ENN200mV R PU Pull-Up Resistor@ pin ENN100kΩDelay Time See Delay on page 6136ms T SHDN Thermal Shutdown Temperature160ºC ∆T SHDN Thermal Shutdown Hysteresis15ºC only valid for AS1720A
V OUT Saturation Voltage, Sink1I OUT = 100mA0.61V
思念的诗句
k Transfer Value R IE = 12kΩ, V DDHV = 5V to 50V, OUT =
1V to 40V (e page 7)108012001320AΩ
I OUT_H Output Hold Current Range1
defined by R IH
(e Figure 10 on page 7)
0.3 x
I OUT_E道德经第三十四章
0.7 x
I OUT_E mA
only valid for AS1720B
Minimum Duty Cycle152025%
Maximum Duty Cycle839095%
Internal Duty Cycle50%
V trig Trigger level to lect internal
voltage divider@ pin DUTY V DDA V
f PWM PWM Frequency25.530 34.5kHz
7 Typical Operating Characteristics
V SUPPLY = 5V, R IE = 30k Ω, R IH = 120k Ω, T AMB = +25ºC (unless otherwi specified);
