ST1CC40PUR STMicroelectronics, ST1CC40PUR Datasheet - Page 6

• Manufacturer Part Number: ST1CC40PUR
• Description: IC CONV DC-DC 3A 4V 8-VFDFPN
• Manufacturer: STMicroelectronics

Specifications of ST1CC40PUR

• Constant Current: Yes
• Internal Driver: Yes
• Type - Primary: General Purpose
• Mounting Type: *
• Topology: PWM, Step-Down (Buck)
• Number Of Outputs: 1
• Frequency: 700kHz ~ 1MHz
• Voltage - Supply: 3.5 V ~ 18 V
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Operating Temperature: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11137-2

Functional description
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Functional description
The ST1CC40 is
capable of generating 3 A constant current output. The architecture of the device is showed
in the block diagram here below.
schottky diode and allows higher efficiency. The ST1CC40 is suitable to drive high power
brightness LEDs.
0.85 MHz Typ switching frequency allows using tiny surface-mount components. The typical
application requires only few external components 3 capacitors and the inductor. The LED
brightness can be controlled by applying a periodic pulse signal to the INH/DIM pin and
varying its duty cycle. This method controls the average light output by pulsing the LED
current between the set value and zero and is called PWM dimming. Inhibit pin is used also
to disable (logic low < 0.4 V) or enable (logic high >1.2 V) the device. It can be connected to
V
150 °C typ.Cycle-by-cycle over-current protection, protect the application and the regulator
against over load outputs. An Internal soft start for start-up current limitation and power on
delay helps to reduce the inrush current during start-up. The ST1CC40 offer 0.1 V Typ
voltage reference with 5% max spread thus minimizes the power loss on the current sensing
resistor.
The output current flowing through the LED string is determined by the value of the resistor
R
R
Where:
●
●
●
Figure 3.
inA
SNS
SNS
if not used. The ST1CC40 is provided with thermal shut down protection activated at
R
V
I
and is calculated by the following Equation:
=V
OUT
FB
SNS
FB
is the reference voltage for the ST1CC40 in Volt (0.1 V typ)
is the desired DC current in the LED string in Ampere
/I
is the value of the sensing resistor
OUT
Block diagram
a constant frequency, current mode regulator with an internal power switch
Doc ID 18279 Rev 1
The synchronous rectification saves the use of an external
ST1CC40