AS1121-BQFT austriamicrosystems, AS1121-BQFT Datasheet - Page 9

• Manufacturer Part Number: AS1121-BQFT
• Description: IC LED DRIVER 16-CH 30V 32-TQFN
• Manufacturer: austriamicrosystems

Specifications of AS1121-BQFT

• Constant Current: Yes
• Internal Driver: Yes
• Type - Primary: Backlight, General Purpose
• Type - Secondary: Color
• Mounting Type: *
• Topology: PWM
• Number Of Outputs: 16
• Voltage - Supply: 3.1 V ~ 3.6 V
• Voltage - Output: 1.5 V ~ 30 V
• Package / Case: *
• Operating Temperature: -40°C ~ 85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency: -
• Other names: AS1121-BQFTTR

AS1121
Datasheet - D e t a i l e d D e s c r i p t i o n
OUTn Enable
All OUTn channels can be collectively switched off with one signal. When OEN is set to 1, all OUTn channels are disabled, regardless of the
device logic operations. The greyscale counter is also reset when OEN is set to 1.
When OEN is set to 0, all OUTn channels are in normal operation.
Table 6. Pin OEN Truth Table
Setting Maximum Channel Current
The maximum output current per channel is programmed by a single resistor, R
on pin I
multiplied by a factor of 31.5. The maximum output current is calculated as:
Where:
V
R
Power Dissipation
To ensure proper operation of the device, the total power dissipation of the AS1121 must be below the power dissipation rating of the device
package. Total power dissipation is calculated as:
Where:
V
I
V
I
DCn is the maximum dot correction value for OUTn;
n is the number of OUTn driving LED at the same time;
d
Operating Modes
The AS1121 operates in two modes
at power-up.
Table 7. Operating Modes
www.austriamicrosystems.com/LED-Driver-ICs
CC
MAX
PWM
IREF
IREF
CC
OUT
is the device supply current;
is the device supply voltage;
is the LED current adjusted by R
is the device OUTn voltage when driving LED current;
= 1.27V;
= User-selected external resistor.
is the duty cycle defined by pin OEN or the greyscale PWM value.
REF
Mode
OEN
is set by an internal band gap V
0
1
0
1
Input Shift Register
Normal Operation
(see Table
OUT0:OUT15
IREF
PD = (V
Disabled
192-bit
96-bit
;
IREF
7). Greyscale operating mode
CC
(1.27V typ). The maximum channel current is equivalent to the current flowing through R
x I
CC
) + (V
I
MAX
OUT
=
Revision 1.00
x I
R
V
IREF
IREF
MAX
x n x
(see Figure 8 on page 11)
x 31.5
IREF
DCn
63
, which is placed between pin I
Dot Correction Data Input Mode
d
PWM
Greyscale PWM Mode
Operating Mode
)
and the shift registers are in reset state
REF
and GND. The voltage
(EQ 1)
(EQ 2)
IREF
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