STCS1APHR STMicroelectronics, STCS1APHR Datasheet - Page 10
![IC LED DRIVR PWM CONTROL PWRSO-8](/photos/7/37/73765/stcs1aphr_sml.jpg)
STCS1APHR
Manufacturer Part Number
STCS1APHR
Description
IC LED DRIVR PWM CONTROL PWRSO-8
Manufacturer
STMicroelectronics
Type
PWM Controlr
Datasheet
1.STCS1APUR.pdf
(19 pages)
Specifications of STCS1APHR
Constant Current
Yes
Topology
PWM
Number Of Outputs
1
Internal Driver
Yes
Type - Primary
Automotive
Type - Secondary
White LED
Voltage - Supply
4.5 V ~ 40 V
Mounting Type
Surface Mount
Package / Case
PowerSO-8
Operating Temperature
-40°C ~ 125°C
Current - Output / Channel
1.5A
Internal Switch(s)
Yes
High Level Output Current
1500 mA
Operating Supply Voltage
4.5 V to 40 V
Maximum Supply Current
3 uA
Maximum Operating Temperature
+ 150 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
- 40 C
For Use With
497-8264 - BOARD EVAL BASED ON STCS1497-5960 - BOARD DEMO FOR STCS1P
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Voltage - Output
-
Frequency
-
Efficiency
-
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
497-6915-2
STCS1APHR
STCS1APHR
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
STCS1APHR
Manufacturer:
RICHTEK
Quantity:
1 001
7
7.1
7.2
7.3
10/19
Detail description
The STCS1A is a BiCMOS constant current source designed to provide a precise constant
current starting from a varying input voltage source. The main target is to replace discrete
components solution for driving LEDs in low voltage applications such as 5 V, 12 V or 24 V
giving benefits in terms of precision, integration and reliability.
Current setting
The current is set with an external sensing resistor connected to the FB pin. The feedback
voltage is 100 mV, then a low resistor value can be chosen reducing power dissipation. A
value between 1 for instance, should one need a 700 mA LEDs current, R
selected according to the following equation:
For instance, should one need a 700 mA LEDs current, R
the following equation:
R
Enable
When the enable pin is low the device completely off thus reducing current consumption to
less than 1 µA. When in shutdown mode, the internal main switch is off.
PWM dimming
The PWM input allows implementing PWM dimming on the LED current; when the PWM
input is high the main switch will be on and vice versa. A typical frequency range for the
input is from few Hertz to 50 kHz. The maximum dimming frequency is limited by the
minimum rise/fall time of the current (obtained with C
Above 50 kHz the current waveforms starts assuming a triangular shape.
While the PWM input is switching, the overall circuitry remains on, this is needed in order to
implement two important features: short delay time and controlled slope for the current.
Since the PWM pin is controlling just the main switch, the overall circuitry is always on and it
is able to control the delay time between the PWM input signal and the output current in the
range of few µs, this is important to implement synchronization among several light LED
sources.
The rise and fall slope of the current is controlled by the C
time are linear dependent from the C
characteristics). A controlled rise time has two main benefits: reducing EMI noise and avoid
current spike at turn on.
When C
condition an overshoot can be present on the LED current before the system goes into
regulation.
F
= V
FB
SLOPE
/ I
LEDs
is left floating, the internal switch is turned on at maximum speed, in this
= 100 mV / 700 mA = 142 mΩ
SLOPE
capacitor value (see graph in typical
SLOPE
F
SLOPE
should be selected according to
= 0) which is around 4µs each.
capacitor. The rise and fall
F
should be