A driver IC with built-in SRAM memory that doubles the perceived refresh rate of scan-type displays with Scrambled-PWM technology.
Macroblock · driver IC, SRAM-integrated S-PWM
Macroblock MBI5253 LED wall component
The MBI5253 is one of Macroblock's more advanced driver ICs with built-in SRAM memory, which allows a complete frame of data to be loaded into the driver at once, after which the IC itself times out the scanning. The manufacturer's Scrambled-PWM (S-PWM) technology breaks the on-time into several shorter sections, which significantly increases the refresh rate perceived by the eye (the effective refresh rate) compared with conventional scan driving.
This function is particularly important on LED walls used with a camera (live broadcast, virtual production, studio shooting with the LED wall behind): at a low effective refresh rate the camera records banding (flicker, roll bar), which an S-PWM driver significantly reduces. The IC also detects open-circuit faults on individual LEDs on its own.
Where the MBI5253 sits in an LED wall system
The S-PWM driver sits in the same place on the rear of the module as any other driver, but it behaves differently in the signal chain: the receiving card loads the frame into the built-in SRAM in one go, and then the chip itself divides the on-time into many short sections. For this, the receiving card (a Colorlight or NovaStar card supporting high refresh, for instance) and the sending controller both have to support the high refresh rate — the driver's capability alone is not enough, and the actual figure is decided in the receiving card's configuration file.
WHEN IT IS THE RIGHT CHOICE
On displays used in front of a camera, in live broadcast or in virtual production (an LED wall as a backdrop for filming), where a high, flicker-free effective refresh rate is a basic requirement.
WHAT TO WATCH OUT FOR
High refresh mode depends on the module's whole signal chain (the controller card and the bandwidth of the cabling too) — the driver IC's capability alone does not guarantee freedom from flicker if the controller card does not support the appropriate refresh rate.
The MBI5253 in practice
The customer sees this in one place only: on camera footage. On a wall with a low effective refresh rate, horizontal bands or a travelling dark stripe (roll bar) appear on the recording, while the wall looks perfect live — so the acceptance test has to be run with the camera and the shutter speed the wall will be used with. Ask for the guaranteed refresh rate in hertz in the quotation (1920 or 3840 Hz, for instance), not just the 'high refresh' designation, because the latter is unmeasurable and unenforceable. In virtual production, synchronising the camera and the wall (genlock) is a separate commissioning task that has to be priced in advance.
Alternatives to the MBI5253
If the wall does not go in front of a camera, the MBI5153 or the ICND2153 gives the same picture quality to the eye, more cheaply — the S-PWM premium does not pay off in that case. On a wall specifically for film and virtual production, however, the controller is also a different category alongside the driver (Brompton, Megapixel), and the end result is decided there, not on the chip. On a very dense grid, the MBI5353 carries the same technology across 48 channels.
MBI5253 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 MBI5253 is a component. With us it works inside these displays — design, manufacturing and installation included.
