SA56202 Datasheet, PDF (8/24 Pages) NXP Semiconductors – One-chip motor driver

Philips Semiconductors
SA56202
One-chip motor driver
Figure 6 depicts the motor voltages V_M1 and V_M2 during accelerating and braking. The
back-EMF voltage is part of these motor voltages.
V_DD(SPN)
V_M1
V_RM
V_DD(SPN)
k
2
0
ω
V_EMF
2
V_EMF
2
ω_max
ω
V_RM
V_M2
0
V_M1
0
V_M2
accelerating
braking
001aaa432
Fig 6. Motor voltages when accelerating and braking with constant motor current.
7.3 Sine generation using True-Silent signals
For the phase relation between the Hall inputs and the spindle outputs in forward rotation,
see Figure 7. These are the signal shapes in sine mode using our True-Silent PWM
technology. The particular shape of the 120° symmetrical U, V and W steering voltages
are because of improved drive strength and improved power efficiency. The drive strength
is improved because with this signal shape a 15 % larger sine can be fit within the supply
rails compared to direct-written sine signals. Also the power efficiency is improved
because this signal shape has 33 % less switching losses compared to a direct-written
sine.
The result is that the motor currents (and motor torques) are pure sine waves generated in
such a way that the motor is driven optimally silent, optimally power efficient and with
maximum driving strength.
9397 750 12772
Preliminary data sheet
Rev. 01 — 19 July 2004
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
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