A 16-channel constant current LED driver with built-in PrecisionDrive technology to eliminate ghosting.
Macroblock · driver IC, 16-channel constant current
Macroblock MBI5124 LED wall component
The Taiwanese company Macroblock is one of the most widespread driver IC manufacturers in the LED display industry. The MBI5124 is a 16-channel constant current driver whose output current is adjustable per channel between 1 and 25 mA at 5V supply and between 1 and 10 mA at 3.3V, and the manufacturer's PrecisionDrive™ technology is specifically optimised for low-current, low-brightness operation (indoor use in a darkened room, for instance).
According to the manufacturer's datasheet, the current deviation between channels is under 2.5% and between chips under 3%, which has real practical significance: the greater this spread, the more the module boundary shows up (a line at the joint between modules) on an even grey or white surface. The IC also contains a built-in precharge circuit to reduce ghosting.
Where the MBI5124 sits in an LED wall system
As many 16-channel drivers sit on a module as there are pixel columns' worth of colour channels to drive; wired in a daisy chain, they pass on the receiving card's serial data stream to one another. On the MBI5124 the grayscale is not produced by the chip on its own but by the receiving card's timing through the output enable (OE) line — picture quality here therefore depends on the joint tuning of the receiving card and the driver, not on the IC alone. Row selection is handled by a separate decoder and switching stage.
WHEN IT IS THE RIGHT CHOICE
On indoor displays that need an even picture at low brightness too (a studio, a meeting room, a shop window), where invisible module boundaries are an important quality expectation.
WHAT TO WATCH OUT FOR
The datasheet current accuracy applies only to the driver IC — for final colour matching the module manufacturer also has to match the bin (production batch) of the lamp beads to the driver; a good driver IC on its own does not correct poor lamp bead sorting.
The MBI5124 in practice
The datasheet's ±2.5% channel and ±3% chip-to-chip spread becomes visible where the modules meet: on an even grey or light pastel picture, a wall with a poor spread shows its module boundaries as grid lines. At the acceptance test, therefore, ask for an even grey test pattern at 20-30% brightness — on white and on moving pictures this fault hides. PrecisionDrive's low-current optimisation is aimed precisely at the situation where an indoor wall is run at a fraction of its nominal brightness; if the wall runs permanently at 100%, this advantage is not realised, while the lamp bead ages faster and the thermal load is higher.
Alternatives to the MBI5124
If the module is scanned and standalone PWM is needed, the Chipone ICND2153 or the Macroblock MBI5153 is its counterpart; for camera use, the MBI5253's S-PWM. Downwards, the ICND2038S is the cheaper entry point, in exchange for being less accurate at low brightness. The more expensive driver pays off where the wall is viewed from close up in a darkened space at low brightness — on an outdoor sign running at full brightness in daylight the difference is practically invisible.
MBI5124 manual and datasheet
The documents live on the manufacturer's own site and open in a new window — so you always get the latest version. We do not copy or translate their contents.
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On its own the Macroblock MBI5124 is a component. With us it works inside these displays — design, manufacturing and installation included.
