TDA5147CH Datasheet, PDF (10/32 Pages) NXP Semiconductors – 12 V Voice Coil Motor VCM driver and spindle motor drive combination chip

Philips Semiconductors
12 V Voice Coil Motor (VCM) driver and
spindle motor drive combination chip
Preliminary specification
TDA5147CH
ENABLE VCM DRIVERS
When V_PCNTL equals V_CC5, the VCM drivers are controlled
by V_IPWMH and V_IPWML. Their duty factor is converted to a
voltage at pin V_FLTOUT. At a 100% duty factor the V_FLTINP
voltage is approximately 1 V above V_refout. At a 0% duty
factor the V_FLTINP voltage is approximately 1 V below
V_refout. At a 50% duty factor, the voltage level is equal to
V_refout (typically 4 V). The V_FLTINP voltage is amplified,
filtered and output at V_FLTOUT. The voltage at V_FLTOUT
varies between ±2 V about V_refout. The V_FLTOUT voltage, in
conjunction with the sense resistor amplifier, drives the
two VCM drivers as illustrated in Fig.4. The equation
describing the transconductance from V_FLTINP to I_coil is:
G_m = -V----_V---_F---_L--_T---_I-_N-I--_Pc---^o--_–ⁱ-^l---V-----_r-_e---_f-_o--_u--_t
= -₍---V----_V---_F---_L---_T--_O--2--_U--I-_T-^c--^o-_–--ⁱ-^l--V----_r--_e--_f-_o---_u--_t--₎-
= 2 × _{g----a-1--i--n-} × ^RR-----21-- × _R---1--S--- A/V
In a typical application:
V-----_F^---_L^---_T^---_I^-_N^---I-_P^-c---o-–^--i-l-V----_r^--_e^---_f^--_o^--_u^---_t ^{= 24-- × 6-1---.-0-6----k-k---}ΩΩ^{--- ×} 0----.-1-3---3-- ^{= 1 A/V}
The transconductance is variable by selecting external
resistors R2/R1 and sense resistors RS.
handbook, full pagewidth
VIPWML ₁
VIPWMH 2
VFLTINP ₃
PWM
DEC
Vrefout
R
R
4 ^VFLTOUT
BUFFER
R1
1997 Jul 09
Vrefout
VCMINP ₄₅
59 ^VCMN
R
ICOIL
M
voice
coil
R
51 ^VCMP
motor
R2
4R
0.5 VCCV12
RS
VISENS1 ₆₁
V1
R
V1
R
4R
Vrefout
60 ^VISENL
57 ^VISENH
MGG846
Fig.4 Transconductance model.
10